Recoil effects on Accuracy

[Ray B]

Longwalker- you are correct. The initial thread involved the effect of barrel movement due primarily to recoil forces while the bullet is in the barrel thus changing the path of the bullet. Unfortunately a few exspurts have attempted to hi-jack the thread and confuse the issue by saying that the effects of recoil are much greater after the bullet has departed. No one is claiming that they aren't, but they are irrelevant to the original topic.

 

[Red Leg]

Longwalker- you are correct. The initial thread involved the effect of barrel movement due primarily to recoil forces while the bullet is in the barrel thus changing the path of the bullet. Unfortunately a few exspurts have attempted to hi-jack the thread and confuse the issue by saying that the effects of recoil are much greater after the bullet has departed. No one is claiming that they aren't, but they are irrelevant to the original topic.

Ray, the thread only seemed to get off topic when other members disagreed with your assertions about lead sleds and their effect on attached optics and accuracy. I am sorry but disagreement with you doesn’t constitute being off topic, however much it apparently angers you. I actually use one a lot, and so my extensive real life experiences would seem to be relevant to others who believed the same thing you apparently do. I would also assert that the various patterns we see on targets have far more to do with shooting technique and where the barrel is pointed at the time of ignition than anything the bullet is doing in the barrel assuming the rifle is inherently accurate to begin with. I am not quite sure why that seems to upset you, and you should feel free to disagree.

@Longwalker you make an excellent point concerning doubles. The maker has two fundamental issues with which to struggle. First, is the inherent accuracy of each load with each respective barrel. Obviously, trying to mate two 3 MOA barrels and loads together would be more challenging than two 1 MOA barrels. Secondly, while the effect of the bullet’s passage is a very small part of managing recoil and recoil’s effect on accuracy, that effect is magnified by the mechanical stresses of the neighboring barrel in a double and does indeed becomes a major issue in regulation. Every other external input seems to further multiply the effect of that interplay.

I would simply contend that comparing recoil management of a single bore rifle and bullet passage effect on regulation are an apples and oranges comparison.

 

[Ray B]

I'm just pointing out that the original discussion involved movement of a gun due to recoil prior to the bullet exiting. for some reason others seem to persist to relate that the movement prior to exit is dwarfed by the movement after exit and shooters technique during the entire firing process. Contrary to one posters accusation I am not angered, amused would be a more accurate term.

 

[Fastrig]

Another super slow video (1,000,000 frames per sec)................ever so slight rearward movement can be detected on the gun. Emphasis on slight. The majority of recoil happens after the bullet leaves the barrel.

This video is 45,000 frames per sec. Looks like the bullet is out of the barrel before significant recoil occurs.

The optimal word there is “slight”. In endeavors involving physics, engineering, etc. when these “slights” are known and they present no consequential effect to the desired outcome, they are often removed from the equation or design because they present nothing more than unnecessary noise. Your videos show that the vast majority of the recoil event takes place after the bullet has left the barrel so the logical conclusion would have to be that the minute amount of recoil energy present while the bullet is in the barrel has an inconsequential effect on the accuracy of the rifle/shot, thus it should be removed from the accuracy equation as it pertains to the physical mechanics of the firing event.

I’ve always said that it’s not the rifle but the shooter that’s the issue, assuming a quality firearm and ammo are being used. My observations over the years have been that recoil is a factor in accuracy, but it is psychological in nature. The shooter is anticipating the recoil/kick of the firing event and that anticipation causes the shooter to do any number of adjustments to the firing position of the end of that barrel PRIOR to the firing event taking place. In short, inaccuracy becomes a PRE-RECOIL event, not a during or post recoil event.

The best example I’ve seen of this was with a friend of mine who swore the 30-06 he bought, because he wanted to try elk hunting, was the most inaccurate rifle he ever owned. Was visiting his place and we were going to the range to do a little plunking while the ladies went shopping. I picked up the 30-06 from his gun cabinet, he tells me not to bother as it’s a piece of junk and can’t hit the side of a barn. I shrugged and said I’d give it a go. He picks up his 30-30 he’s been shooting for years. We get to the range and set up next to each other and he proceeds to tight group his first three shots at a 100 with his 30-30, something I’ve seen him do quite often. I setup with the 30-06 and do the same on the next target. His jaw dropped. He asked what I did to the rifle to get it to shoot like that, I hadn’t done anything to it. He bought it used and whoever had it before had obviously dialed it in properly. I handed it to him and said it seems okay to me and to give it a try. He sets up to shoot it and guess what? Yep, all the relaxed and proper shooting mechanics he has with his 30-30 seemed to dissolve into thin air. His three shots are off a good 7-8 inches from mine and he’s giving me a look like “what the hell?!”. Asked him if the 30-06 was the hardest recoiling rifle he’s ever shot, he said it was. I explained that I was watching him and his mechanics went right out the window as soon as he sat down at the bench with that rifle, he didn’t even realize it. Turns out he’s a bit recoil sensitive. We spent the next hour working with that rifle and he was starting to put his shots closer and closer to mine. At the end of the day, recoil effect on that bullet traveling down the barrel, zero, pre-recoil effect on that bullet traveling down that barrel, 100%.

 

[One Day...]

0.016 degree (1.6 hundredth of 1 degree)...

I have a long and justified professional reputation for having an open mind and being able to change my mind and adopt the other guy's better idea once the other guy convinces me that his idea is better, so this is the frame of mind I am in when writing/reading this thread. Besides, there is genuinely no reason for this dialog to be anything but cordial...

So, where are we?

1) We all agree, I believe, that an overwhelming proportion of shooting accuracy resides in the shooter, not in the firearm. I do not believe that anyone is arguing against this.

2) We also all agree, I believe, that an overwhelming proportion of recoil happens after the bullet leaves the barrel. I do not believe that anyone is arguing against this.

3) We all agree too, I believe, that rifle and bullet motions in opposite direction are simultaneous, and that the firearm/barrel/slide moves back, not much indeed, but some, as the bullet moves forward. I do not believe that anyone is arguing against this.​

So, neither psychological nor physical recoil principles are in debate.

What is in debate is how much influence the however small movement of the firearm has while the bullet is still in the barrel, and as it is living it, and whether this movement is relevant compared to other factors of inaccuracy.

Having read the various inputs with an open mind, and watched the videos carefully, I have the following question:

Do rifles with considerably more recoil than the 6.5 Creedmoor (shown in the video) recoil, move, jump, etc. more while the bullet is still in the barrel? For example, if that Creedmoor load (say 140 gr bullet at 2,700 fps) generates 10.6 ft/lbs of recoil at 8.7 fps in a 9 lbs rifle, and has apparently zero or near zero effect on the rifle before it leaves the barrel, is this also true for a .340 Wby shooting a 250 gr bullet at 2,940 fps and generating 43.4 ft/lbs of recoil at 17.6 fps from also a 9 lbs. rifle? Is 4 times the recoil force at twice the recoil speed moving the barrel significantly more and significantly faster? One would intuitively think so, but does it move the barrel enough and fast enough to have a significant impact on accuracy?​

The reason I ask this question is as follows:

We will all agree readily, I believe, that in the US our shooting accuracy is typically measured in "minute of angle" (MOA), with 1 MOA measuring approximately 1" at 100 yards.

Here is my point: in order to create a 1 MOA divergence, all the barrel tip needs to move under recoil is 0.016 degree. It bears repeating: if the barrel moves 1.6 hundredth of 1 degree under recoil while the bullet is still in it, the outcome at 100 yards will be 1 inch.

I cannot prove it because I do not have the equipment to film at ultra high speed the barrel of a .300, .338, .375. 416, 458 etc. but I believe from experience that high and fast recoil rifles are quite likely to move enough under recoil while the bullet is still in the barrel, for the barrel tip to move upward or sideways a few hundredths of a degree.

If this was not the case, I would shoot my .340 Wby as well as I shoot my .257 Wby, but I do not, and the issue in my case, I am pretty certain, is not a breakdown in shooting technique, because with a recoil shield the .340 does not hurt me and I do not fear it.

If this was not the case also, the very concept of "barrel timing" would indeed be irrelevant to double rifles regulation, and regulation groups would not open or close on demand by increasing or decreasing the powder charge or using powders with slower or faster burn rates.

I am open to be convinced otherwise, and

• yes I agree that most of recoil takes place after the bullet is long gone,
• yes I agree that recoil physical effects (pain) create all sorts of psychological effects (fear) that result in a long list of shooting technique breakdowns,
• yes I agree that a recoil anticipation trigger jerk flinch or a host of other possible things before ignition will result in much larger groups than anything that can happen while the powder is burning,
• etc.

but we are not discussing an "either / or" recoil scenario, we are discussing an "all-of-the-above" recoil scenario.

I personally believe that with high and fast recoil rifles shot from positions where recoil is human-controlled, it is quite likely that the barrel tip will move a few hundredths of a degree before the bullet is out, and this alone is enough to open a 1" group to 2" or 3" inches at 100 yd.

This, I believe, is the fact behind the common sense wisdom that hard & fast recoil rifles, especially the DG rifles, are harder to shoot well than low recoil rifles like the 6.5 Creedmoor.

I also personally believe that a led sled that combines recoil absorption with rigid mechanical control of both forearm and rear stock is likely to provide more control over a few hundredths of a degree barrel tip move than a field position, which is the reason why I believe that, for most shooters, getting off the sled will both open the group and move the group.

This being said, I am not trying to convince anyone and I am open to being convinced otherwise, but 0.016 degree of barrel tip movement is indeed not very much

 

[Ray B]

Simple test:

Take a lead sled. Cut a clock of wood so that it will fit in the pocket that holds the rifle butt. Cut the portion of the block that faces forward (the part that actually contacts the stock) at a 45 degree angle in the vertical plane. Placing the rifle on the lead sled, the butt should contact the block on the forward edge and as the rifle would recoil it would slide back and to the side. Now when fired if the bullet was out of the barrel before the rifle recoiled there would be no difference in the direction taken by the bullets. However if the rifle responded to established laws of physics the bullet would travel in the direction opposite to that taken by the butt. Someone with a lead sled could give this a try and report their findings.

 

[Standard Velocity]

0.016 degree (1.6 hundredth of 1 degree)...

I have a long and justified professional reputation for having an open mind and being able to change my mind and adopt the other guy's better idea once the other guy convinces me that his idea is better, so this is the frame of mind I am in when writing/reading this thread. Besides, there is genuinely no reason for this dialog to be anything but cordial...

So, where are we?

1) We all agree, I believe, that an overwhelming proportion of shooting accuracy resides in the shooter, not in the firearm. I do not believe that anyone is arguing against this.

2) We also all agree, I believe, that an overwhelming proportion of recoil happens after the bullet leaves the barrel. I do not believe that anyone is arguing against this.

3) We all agree too, I believe, that rifle and bullet motions in opposite direction are simultaneous, and that the firearm/barrel/slide moves back, not much indeed, but some, as the bullet moves forward. I do not believe that anyone is arguing against this.​

So, neither psychological nor physical recoil principles are in debate.

What is in debate is how much influence the however small movement of the firearm has while the bullet is still in the barrel, and as it is living it, and whether this movement is relevant compared to other factors of inaccuracy.

Having read the various inputs with an open mind, and watched the videos carefully, I have the following question:

Do rifles with considerably more recoil than the 6.5 Creedmoor (shown in the video) recoil, move, jump, etc. more while the bullet is still in the barrel? For example, if that Creedmoor load (say 140 gr bullet at 2,700 fps) generates 10.6 ft/lbs of recoil at 8.7 fps in a 9 lbs rifle, and has apparently zero or near zero effect on the rifle before it leaves the barrel, is this also true for a .340 Wby shooting a 250 gr bullet at 2,940 fps and generating 43.4 ft/lbs of recoil at 17.6 fps from also a 9 lbs. rifle? Is 4 times the recoil force at twice the recoil speed moving the barrel significantly more and significantly faster? One would intuitively think so, but does it move the barrel enough and fast enough to have a significant impact on accuracy?​

The reason I ask this question is as follows:

We will all agree readily, I believe, that in the US our shooting accuracy is typically measured in "minute of angle" (MOA), with 1 MOA measuring approximately 1" at 100 yards.

Here is my point: in order to create a 1 MOA divergence, all the barrel tip needs to move under recoil is 0.016 degree. It bears repeating: if the barrel moves 1.6 hundredth of 1 degree under recoil while the bullet is still in it, the outcome at 100 yards will be 1 inch.

I cannot prove it because I do not have the equipment to film at ultra high speed the barrel of a .300, .338, .375. 416, 458 etc. but I believe from experience that high and fast recoil rifles are quite likely to move enough under recoil while the bullet is still in the barrel, for the barrel tip to move upward or sideways a few hundredths of a degree.

If this was not the case, I would shoot my .340 Wby as well as I shoot my .257 Wby, but I do not, and the issue in my case, I am pretty certain, is not a breakdown in shooting technique, because with a recoil shield the .340 does not hurt me and I do not fear it.

If this was not the case also, the very concept of "barrel timing" would indeed be irrelevant to double rifles regulation, and regulation groups would not open or close on demand by increasing or decreasing the powder charge or using powders with slower or faster burn rates.

I am open to be convinced otherwise, and

• yes I agree that most of recoil takes place after the bullet is long gone,
• yes I agree that recoil physical effects (pain) create all sorts of psychological effects (fear) that result in a long list of shooting technique breakdowns,
• yes I agree that a recoil anticipation trigger jerk flinch or a host of other possible things before ignition will result in much larger groups than anything that can happen while the powder is burning,
• etc.

but we are not discussing an "either / or" recoil scenario, we are discussing an "all-of-the-above" recoil scenario.

I personally believe that with high and fast recoil rifles shot from positions where recoil is human-controlled, it is quite likely that the barrel tip will move a few hundredths of a degree before the bullet is out, and this alone is enough to open a 1" group to 2" or 3" inches at 100 yd.

This, I believe, is the fact behind the common sense wisdom that hard & fast recoil rifles, especially the DG rifles, are harder to shoot well than low recoil rifles like the 6.5 Creedmoor.

I also personally believe that a led sled that combines recoil absorption with rigid mechanical control of both forearm and rear stock is likely to provide more control over a few hundredths of a degree barrel tip move than a field position, which is the reason why I believe that, for most shooters, getting off the sled will both open the group and move the group.

This being said, I am not trying to convince anyone and I am open to being convinced otherwise, but 0.016 degree of barrel tip movement is indeed not very much

I like your logic and believe you are correct. Any small or seemingly negligible change in bore axis will have an affect that increases exponentially with distance to the target.

I would add that there is a huge difference in lock time between different mechanisms and even those with different weight firing pins. In dry firing I do notice a degree of recoil that would exist long before bullet exit. Granted, the impact on the primer would cushion this impact but a long lock time and a heavy firing pin can have it’s own impact on accuracy.

There is also the fact that there is a controlled explosion in the chamber before the bullet exits. Recoil moves the rifle backward in a fairly straight line (with any bearing surfaces causing it to bounce around a bit). During firing there are oscillations of the barrel and action which are containing the pressure.

Certainly there are a few things happening before the bullet clears the muzzle. Surely the biggest thing happening occurs between the ears but enough little things are stacking up well before we notice the recoil.

 

[Red Leg]

Simple test:

Take a lead sled. Cut a clock of wood so that it will fit in the pocket that holds the rifle butt. Cut the portion of the block that faces forward (the part that actually contacts the stock) at a 45 degree angle in the vertical plane. Placing the rifle on the lead sled, the butt should contact the block on the forward edge and as the rifle would recoil it would slide back and to the side. Now when fired if the bullet was out of the barrel before the rifle recoiled there would be no difference in the direction taken by the bullets. However if the rifle responded to established laws of physics the bullet would travel in the direction opposite to that taken by the butt. Someone with a lead sled could give this a try and report their findings.

This whole lead sled thing is vexing for you isn’t it Ray.

Not tracking what point you are trying to make. Neither my shoulder nor a lead sled butt rest is so angled.

Look, I agree that there is some relatively small recoil effect caused while the bullet is still in the barrel. That was the point of the first bit of math that I offered. However, I have yet to see any actual evidence that it is particularly meaningful with respect to where he bullet lands on target, and there is considerable evidence to the contrary. And yes, I understand that is also contrary to a lot of conventional wisdom.

I believe, on the other hand, that the recoil event in its totality has enormous effect on where the shooter is actually pointing the bore shot to shot. The things the shooter must do to overcome response to recoil are exactly the same whatever the bullet is doing and whenever it is doing it. We can likely agree on that.

@One Day... makes a potentially good point with respect to heavy calibers. Overcoming initial inertia requires greater force as the weight of the projectile and powder charge increase. Of course, so does the force of the overall recoil event. Group size may indeed increase somewhat because the internal ballistics are more dramatic, or it may simply be we don’t much like getting hit harder than a 6.5. I tend to believe the latter, but time lapse photography of a .375 or .416 likely would be instructive.

Regardless, we are going to do the same things to try and overcome shot to shot dispersion. I just find it more honest to say my .338 groups suck not because I am shooting a bigger rifle but because my shooting technique sucks when shooting it.

 

[mark-hunter]

If the total "error" of each shot is lets say within 1 moa, or gouping of 1 inch at 100 yards, then it is total error, only.
The total error is the sum of all known and unknown variables.
We should strive to minimize the effect of known variables, and reduce the number of unknowns.

Recoil is only one of the possible variables.

In theoretical perfect firearm, variables should be eliminated to get maximum consistency, how ever, it is not yet technologically possible.

- recoil: what are the weight tolerances of each bullet, different weight of bullet, will make different velocity, different recoil, different point of impact.
(weight of bullet could be within 3 or 4 or 5 or 6 decimals, but the weight will vary, and deviations will be more visible on lower quality bullets, with wider range of weight.

- individuality of gun: on one of movie clips earlier, we have seen colt 1911 in recoil motion.
Biggest recoil was after the bullet leaves the barrel. However, there are moving parts, barrel included.
Make that pistol, match grade, same weight and shape, but with smaller tolerances of moving parts, tighter bushing in front, the group will be smaller (with same recoil, or same bullet), but never the less, there will be spread of POI.
- For long guns, shape of stock will make different recoil jump. Straight type stock, hog back, monte carlo, etc... It is directly related to position of center of gravity of barrel where recoil happens, to the center of gravity of entire firearm platform, and shape of stock will determine final recoil jump.

- individuality of shooter, effected by recoil.

- heating of the barrel, spreading the group size.

- other: powder charge. Although not related directly to recoil, but will effect group size, due to varilbles of muzzle velocities.

In conclusion:
We cannot keep consistency from each to each shot due to all things never being equal, or repeatable and total error cannot be contributed to only one variable (like recoil), but to the sum of all of them.
What we can do is try to analyse each variable, and minimize each negative effect.

However there are some guidelines from from target shooting sports.
generally, most accurate target rifles or pistols, are as heavy as possible, or as heavy as match rules will allow.
Heavy gun, will have smaller recoil, and will tend to make better accuracy then average. (can we take this as a fact, or just as a guideline?)

So, most probably, in the gun designers mind or consensus, the recoil is negative to accuracy performance, but certainly there is no mathematical formula to define this effect, just yet.

The test?
Writing this, I came to following idea:
to make meaningful test is to have a single firearm, which can change the recoil, without changing weight or barrel harmonics, and then to make the test.
Well, I have just that, but I am sure others will have, as well. And the real test is possible.

To improve accuracy for match pistols they can be fitted with recoil reducer, which is slide spring guide, fitted with additional spring, to further reduce recoil.
It can also be argued, that reducing recoil in match pistol, is for the purpose of easier control of pistol during rapid fire part of match, not to improve inherent accuracy, but never the less it is here.

Having said that, I have an idea of actual test to perform.
For my match pistol, I have both - the standard spring guide, and slide recoil reducer spring guide.

So the test can be made with identical pistol using two different slide spring guides.
When I get a chance, as I am presently at work, I will try to make the test, check the group sizes and let you guys know what I have discovered.
(But first: I need to get from work, and public range has to be open, depending of c-19 restrictions, and it will take some time)

Anybody who has similar equipment can do it in the meantime.
To eliminate shooters individual error, the shooting should be done from some kind of rest.

Rifles with mercury recoil reducers could be used in a similar way, except that recoil reducers should be changed with something of same weight, who ever is willing to try, and post results.

 

[375 Ruger Fan]

0.016 degree (1.6 hundredth of 1 degree)...

I have a long and justified professional reputation for having an open mind and being able to change my mind and adopt the other guy's better idea once the other guy convinces me that his idea is better, so this is the frame of mind I am in when writing/reading this thread. Besides, there is genuinely no reason for this dialog to be anything but cordial...

So, where are we?

1) We all agree, I believe, that an overwhelming proportion of shooting accuracy resides in the shooter, not in the firearm. I do not believe that anyone is arguing against this.

2) We also all agree, I believe, that an overwhelming proportion of recoil happens after the bullet leaves the barrel. I do not believe that anyone is arguing against this.

3) We all agree too, I believe, that rifle and bullet motions in opposite direction are simultaneous, and that the firearm/barrel/slide moves back, not much indeed, but some, as the bullet moves forward. I do not believe that anyone is arguing against this.​

So, neither psychological nor physical recoil principles are in debate.

What is in debate is how much influence the however small movement of the firearm has while the bullet is still in the barrel, and as it is living it, and whether this movement is relevant compared to other factors of inaccuracy.

Having read the various inputs with an open mind, and watched the videos carefully, I have the following question:

Do rifles with considerably more recoil than the 6.5 Creedmoor (shown in the video) recoil, move, jump, etc. more while the bullet is still in the barrel? For example, if that Creedmoor load (say 140 gr bullet at 2,700 fps) generates 10.6 ft/lbs of recoil at 8.7 fps in a 9 lbs rifle, and has apparently zero or near zero effect on the rifle before it leaves the barrel, is this also true for a .340 Wby shooting a 250 gr bullet at 2,940 fps and generating 43.4 ft/lbs of recoil at 17.6 fps from also a 9 lbs. rifle? Is 4 times the recoil force at twice the recoil speed moving the barrel significantly more and significantly faster? One would intuitively think so, but does it move the barrel enough and fast enough to have a significant impact on accuracy?​

The reason I ask this question is as follows:

We will all agree readily, I believe, that in the US our shooting accuracy is typically measured in "minute of angle" (MOA), with 1 MOA measuring approximately 1" at 100 yards.

Here is my point: in order to create a 1 MOA divergence, all the barrel tip needs to move under recoil is 0.016 degree. It bears repeating: if the barrel moves 1.6 hundredth of 1 degree under recoil while the bullet is still in it, the outcome at 100 yards will be 1 inch.

I cannot prove it because I do not have the equipment to film at ultra high speed the barrel of a .300, .338, .375. 416, 458 etc. but I believe from experience that high and fast recoil rifles are quite likely to move enough under recoil while the bullet is still in the barrel, for the barrel tip to move upward or sideways a few hundredths of a degree.

If this was not the case, I would shoot my .340 Wby as well as I shoot my .257 Wby, but I do not, and the issue in my case, I am pretty certain, is not a breakdown in shooting technique, because with a recoil shield the .340 does not hurt me and I do not fear it.

If this was not the case also, the very concept of "barrel timing" would indeed be irrelevant to double rifles regulation, and regulation groups would not open or close on demand by increasing or decreasing the powder charge or using powders with slower or faster burn rates.

I am open to be convinced otherwise, and

• yes I agree that most of recoil takes place after the bullet is long gone,
• yes I agree that recoil physical effects (pain) create all sorts of psychological effects (fear) that result in a long list of shooting technique breakdowns,
• yes I agree that a recoil anticipation trigger jerk flinch or a host of other possible things before ignition will result in much larger groups than anything that can happen while the powder is burning,
• etc.

but we are not discussing an "either / or" recoil scenario, we are discussing an "all-of-the-above" recoil scenario.

I personally believe that with high and fast recoil rifles shot from positions where recoil is human-controlled, it is quite likely that the barrel tip will move a few hundredths of a degree before the bullet is out, and this alone is enough to open a 1" group to 2" or 3" inches at 100 yd.

This, I believe, is the fact behind the common sense wisdom that hard & fast recoil rifles, especially the DG rifles, are harder to shoot well than low recoil rifles like the 6.5 Creedmoor.

I also personally believe that a led sled that combines recoil absorption with rigid mechanical control of both forearm and rear stock is likely to provide more control over a few hundredths of a degree barrel tip move than a field position, which is the reason why I believe that, for most shooters, getting off the sled will both open the group and move the group.

This being said, I am not trying to convince anyone and I am open to being convinced otherwise, but 0.016 degree of barrel tip movement is indeed not very much

Great summary, I can live with this. BTW, prior to this discussion and other similar ones, I was of the opinion that recoil had a more significant role in accuracy. But by studying it, doing some research and keeping an open mind, I changed my opinion based on the data and analysis.

 

[375 Ruger Fan]

A few other forces at work that haven't been mentioned:

In a bolt action rifle, the potential energy from a spring is converted to kinetic energy and transferred to the firing pin. The firing pin is a mass of steel that then has a collision with the firing pin. Shouldn't the entire rifle be driven forward, albeit a very minute amount?

Second random thought: The bullet has torque applied to it by the riflings in the barrel, creating spin. The bullet goes from 0 rpm to over 200,000 rpm, give or take. It seems there should be a reactionary force on the rifle, opposite and equal too the force being applied to the bullet. What affect, if any doe this have on accuracy?

Lastly, if shooting a big bore from a Lead Sled, located on the island of Guam, would the recoil contribute to the potential capsizing and/or sinking of the island?

 

[Shootist43]

Been reading this for days, aside from all of the theories and facts presented to me the simple answer is "of course it does" for some more than others.

 

[fourfive8]

A few other forces at work that haven't been mentioned:

Lastly, if shooting a big bore from a Lead Sled, located on the island of Guam, would the recoil contribute to the potential capsizing and/or sinking of the island?

Been there, done Guam a couple times. If the shot were 90 degrees to the island's axis and on top of the central highlands near the "waistline" of Guam.... just might do it!

 

[Fastrig]

0.016 degree (1.6 hundredth of 1 degree)...

I have a long and justified professional reputation for having an open mind and being able to change my mind and adopt the other guy's better idea once the other guy convinces me that his idea is better, so this is the frame of mind I am in when writing/reading this thread. Besides, there is genuinely no reason for this dialog to be anything but cordial...

So, where are we?

1) We all agree, I believe, that an overwhelming proportion of shooting accuracy resides in the shooter, not in the firearm. I do not believe that anyone is arguing against this.

2) We also all agree, I believe, that an overwhelming proportion of recoil happens after the bullet leaves the barrel. I do not believe that anyone is arguing against this.

3) We all agree too, I believe, that rifle and bullet motions in opposite direction are simultaneous, and that the firearm/barrel/slide moves back, not much indeed, but some, as the bullet moves forward. I do not believe that anyone is arguing against this.​

So, neither psychological nor physical recoil principles are in debate.

What is in debate is how much influence the however small movement of the firearm has while the bullet is still in the barrel, and as it is living it, and whether this movement is relevant compared to other factors of inaccuracy.

Having read the various inputs with an open mind, and watched the videos carefully, I have the following question:

Do rifles with considerably more recoil than the 6.5 Creedmoor (shown in the video) recoil, move, jump, etc. more while the bullet is still in the barrel? For example, if that Creedmoor load (say 140 gr bullet at 2,700 fps) generates 10.6 ft/lbs of recoil at 8.7 fps in a 9 lbs rifle, and has apparently zero or near zero effect on the rifle before it leaves the barrel, is this also true for a .340 Wby shooting a 250 gr bullet at 2,940 fps and generating 43.4 ft/lbs of recoil at 17.6 fps from also a 9 lbs. rifle? Is 4 times the recoil force at twice the recoil speed moving the barrel significantly more and significantly faster? One would intuitively think so, but does it move the barrel enough and fast enough to have a significant impact on accuracy?​

The reason I ask this question is as follows:

We will all agree readily, I believe, that in the US our shooting accuracy is typically measured in "minute of angle" (MOA), with 1 MOA measuring approximately 1" at 100 yards.

Here is my point: in order to create a 1 MOA divergence, all the barrel tip needs to move under recoil is 0.016 degree. It bears repeating: if the barrel moves 1.6 hundredth of 1 degree under recoil while the bullet is still in it, the outcome at 100 yards will be 1 inch.

I cannot prove it because I do not have the equipment to film at ultra high speed the barrel of a .300, .338, .375. 416, 458 etc. but I believe from experience that high and fast recoil rifles are quite likely to move enough under recoil while the bullet is still in the barrel, for the barrel tip to move upward or sideways a few hundredths of a degree.

If this was not the case, I would shoot my .340 Wby as well as I shoot my .257 Wby, but I do not, and the issue in my case, I am pretty certain, is not a breakdown in shooting technique, because with a recoil shield the .340 does not hurt me and I do not fear it.

If this was not the case also, the very concept of "barrel timing" would indeed be irrelevant to double rifles regulation, and regulation groups would not open or close on demand by increasing or decreasing the powder charge or using powders with slower or faster burn rates.

I am open to be convinced otherwise, and

• yes I agree that most of recoil takes place after the bullet is long gone,
• yes I agree that recoil physical effects (pain) create all sorts of psychological effects (fear) that result in a long list of shooting technique breakdowns,
• yes I agree that a recoil anticipation trigger jerk flinch or a host of other possible things before ignition will result in much larger groups than anything that can happen while the powder is burning,
• etc.

but we are not discussing an "either / or" recoil scenario, we are discussing an "all-of-the-above" recoil scenario.

I personally believe that with high and fast recoil rifles shot from positions where recoil is human-controlled, it is quite likely that the barrel tip will move a few hundredths of a degree before the bullet is out, and this alone is enough to open a 1" group to 2" or 3" inches at 100 yd.

This, I believe, is the fact behind the common sense wisdom that hard & fast recoil rifles, especially the DG rifles, are harder to shoot well than low recoil rifles like the 6.5 Creedmoor.

I also personally believe that a led sled that combines recoil absorption with rigid mechanical control of both forearm and rear stock is likely to provide more control over a few hundredths of a degree barrel tip move than a field position, which is the reason why I believe that, for most shooters, getting off the sled will both open the group and move the group.

This being said, I am not trying to convince anyone and I am open to being convinced otherwise, but 0.016 degree of barrel tip movement is indeed not very much

First and foremost, I’d like to say that was EXTREMELY well written and those are very good questions for everyone to consider with, as you aptly stated, an open mind. In response, and with the understanding that I’m a hunter who uses bolt and semi-auto rifles, not ballistics guru, I think we have to look at all the factors involved in shooting accuracy, holistically as well as empirically, and to what extent each truly effects where the bullet strikes.

Having said that, we agree that the recoil event is extremely slight during the period of time the bullet is traveling in the barrel, an empirical item. We can also agree that a very slight movement of the barrel, hundredth of an inch, will effect where that bullet lands, both empirical and holistic items. The issue I personally have with the empirical side, is the lack of measurable data on how or if recoil energy while the bullet is traveling in the barrel is effecting barrel direction. There may be some, but I haven’t seen it. I believe someone else in an earlier thread said this would be extremely hard to measure. So with the lack of empirical data to draw upon, I have to look at field observations that I have experienced to draw my personal conclusions, not that those are spot on but they do form my opinion and input into this discussion so should be taken with a grain of salt.

Last year I purchased two new rifles, a Mauser M12 Max in 9.3x62 and a Merkel RX Helix in 300 win mag. Neither is a precision shooter, they are hunting rifles and I don’t expect half MOA accuracy from them. I dialed both in at 100 yards, though I want to redial the 300 win mag in at 150 at some point. I used a lead sled, weighted with a bag of shot, as I find doing so provides the most stable platform and, thus, the best results. Off the sled, which is taking much of my human element out of the equation as possible, I got them both firing .75 to 1.25 groups, depending on bullets used. Now for a hunting rifle, that’s plenty accurate. If there is any recoil factor here, IMO, it isn’t enough to worry about when I’ve got a couple of hunting rifles producing these kind of groupings at 100 yards.

NOW, take these rifles off the sled and put them into my happy tail hands. This is where my opinion on this topic, via field and self observation, is honestly formed. Starting with Mauser 9.3x62, my first shot was half inch off bullseye, not bad. Second shot, an inch off bullseye, still not bad. Third, fourth and fifth shot, roughly two to two and half inches off bullseye, hmmmmm. I’m thinking, What the hell is going on here. Yes, the barrel has heated up a bit with five rounds, though I did wait a couple of minutes between shots. Is that really effecting these shots? I then did a little self evaluation. This M12 Max is LIGHT, 8.5 lbs with scope and loaded, so it gives you a pretty good push when you pull the trigger, especially off a bench. Am I doing something here causing this drift? I didn’t think I was as I felt very relaxed when setting up for the shots, but decided to ask the range master to observe my next couple of shots to get his input. Sure enough, he said that I was relaxed and all setup for the shot but just before I pulled the trigger I was pulling that rifle in just a touch more into my shoulder. Let the rifle cool a bit, loaded a couple more rounds, then concentrated on not adjusting, both shots half inch off bullseye. Put the 9.3 aside and picked up the 300 win mag. Now this RX Helix has to be the softest shooting 300 wm I’ve ever shot. Like the Mauser, she is light, but the recoil is more akin to my old 308 win, a tad more but not much. First shot, dead center bullseye. Next two shots within .75 of bullseye. Not one shot out of the Helix was more than an inch off the rest of the day. She’s a pleasure to shoot.

Personal Conclusions: Shooting accuracy, from a quality rifle that’s dialed in properly (which both of mine are/were), is inherently a shooter item, the holistic side, rather than the empirical mechanical side of the equation. If there is any effect from the recoil event on that bullet exiting the barrel, it is so negligible as to be a non-factor, IMO. On the other end of the equation, the holistic human factors, adjustments, and psychological influence on accuracy is where issues truly arise. I’m not recoil sensitive, but I’ve got a torn up shooting shoulder and the 9.3 was making me psychologically adjust my normal shooting setup in anticipation of the recoil, and it only took one shot to do that, while the soft shooting Helix didn’t. Once I was aware of what was transpiring with the 9.3, I was able to overcome it with a bit of practice and don’t have the issue any longer. That Mauser has become one of my favorite rifles. When someone says, “it’s all in your head”, that often times is exactly correct. My experience with the 9.3, the example of my friend and his 30-06, and any number of other times I’ve observed what I call “recoil flinch” in people, tells me that it’s the shooter 99.x% of the time, not the rifle.

 

[Red Leg]

First and foremost, I’d like to say that was EXTREMELY well written and those are very good questions for everyone to consider with, as you aptly stated, an open mind. In response, and with the understanding that I’m a hunter who uses bolt and semi-auto rifles, not ballistics guru, I think we have to look at all the factors involved in shooting accuracy, holistically as well as empirically, and to what extent each truly effects where the bullet strikes.

Having said that, we agree that the recoil event is extremely slight during the period of time the bullet is traveling in the barrel, an empirical item. We can also agree that a very slight movement of the barrel, hundredth of an inch, will effect where that bullet lands, both empirical and holistic items. The issue I personally have with the empirical side, is the lack of measurable data on how or if recoil energy while the bullet is traveling in the barrel is effecting barrel direction. There may be some, but I haven’t seen it. I believe someone else in an earlier thread said this would be extremely hard to measure. So with the lack of empirical data to draw upon, I have to look at field observations that I have experienced to draw my personal conclusions, not that those are spot on but they do form my opinion and input into this discussion so should be taken with a grain of salt.

Last year I purchased two new rifles, a Mauser M12 Max in 9.3x62 and a Merkel RX Helix in 300 win mag. Neither is a precision shooter, they are hunting rifles and I don’t expect half MOA accuracy from them. I dialed both in at 100 yards, though I want to redial the 300 win mag in at 150 at some point. I used a lead sled, weighted with a bag of shot, as I find doing so provides the most stable platform and, thus, the best results. Off the sled, which is taking much of my human element out of the equation as possible, I got them both firing .75 to 1.25 groups, depending on bullets used. Now for a hunting rifle, that’s plenty accurate. If there is any recoil factor here, IMO, it isn’t enough to worry about when I’ve got a couple of hunting rifles producing these kind of groupings at 100 yards.

NOW, take these rifles off the sled and put them into my happy tail hands. This is where my opinion on this topic, via field and self observation, is honestly formed. Starting with Mauser 9.3x62, my first shot was half inch off bullseye, not bad. Second shot, an inch off bullseye, still not bad. Third, fourth and fifth shot, roughly two to two and half inches off bullseye, hmmmmm. I’m thinking, What the hell is going on here. Yes, the barrel has heated up a bit with five rounds, though I did wait a couple of minutes between shots. Is that really effecting these shots? I then did a little self evaluation. This M12 Max is LIGHT, 8.5 lbs with scope and loaded, so it gives you a pretty good push when you pull the trigger, especially off a bench. Am I doing something here causing this drift? I didn’t think I was as I felt very relaxed when setting up for the shots, but decided to ask the range master to observe my next couple of shots to get his input. Sure enough, he said that I was relaxed and all setup for the shot but just before I pulled the trigger I was pulling that rifle in just a touch more into my shoulder. Let the rifle cool a bit, loaded a couple more rounds, then concentrated on not adjusting, both shots half inch off bullseye. Put the 9.3 aside and picked up the 300 win mag. Now this RX Helix has to be the softest shooting 300 wm I’ve ever shot. Like the Mauser, she is light, but the recoil is more akin to my old 308 win, a tad more but not much. First shot, dead center bullseye. Next two shots within .75 of bullseye. Not one shot out of the Helix was more than an inch off the rest of the day. She’s a pleasure to shoot.

Personal Conclusions: Shooting accuracy, from a quality rifle that’s dialed in properly (which both of mine are/were), is inherently a shooter item, the holistic side, rather than the empirical mechanical side of the equation. If there is any effect from the recoil event on that bullet exiting the barrel, it is so negligible as to be a non-factor, IMO. On the other end of the equation, the holistic human factors, adjustments, and psychological influence on accuracy is where issues truly arise. I’m not recoil sensitive, but I’ve got a torn up shooting shoulder and the 9.3 was making me psychologically adjust my normal shooting setup in anticipation of the recoil, and it only took one shot to do that, while the soft shooting Helix didn’t. Once I was aware of what was transpiring with the 9.3, I was able to overcome it with a bit of practice and don’t have the issue any longer. That Mauser has become one of my favorite rifles. When someone says, “it’s all in your head”, that often times is exactly correct. My experience with the 9.3, the example of my friend and his 30-06, and any number of other times I’ve observed what I call “recoil flinch” in people, tells me that it’s the shooter 99.x% of the time, not the rifle.

 

[One Day...]

Simple test ... if the bullet was out of the barrel before the rifle recoiled there would be no difference in the direction taken by the bullets. However if the rifle responded to established laws of physics the bullet would travel in the direction opposite to that taken by the butt. Someone with a lead sled could give this a try and report their findings.

I see your point, Ray B. If the rifle is made purposefully to recoil sideways, this will prove one of the two theories: POI is affected, or POI is not affected, i.e. the barrel is pointing sideways before the bullet leaves it, or the bullet leaves before the barrel points sideways.

@One Day... makes a potentially good point with respect to heavy calibers. Overcoming initial inertia requires greater force as the weight of the projectile and powder charge increase.

This is the only explanation that I can come with to the very real concept of "barrel timing" for double rifles regulation. Nitro Express calibers may be the best example: extremely heavy bullet, extremely large powder charge, extremely large recoil (an 11 lbs .470 N.E. rifle launching a 500 gr bullet at 2150 fps, produces 69.3 ft/lbs of recoil at 20.1 fps - now we are talking 6.5 times the force and 2.3 times the speed of the 6.5 Creedmoor recoil), combined with slow bullet speed, i.e. longer time in the barrel.

These ought to have an effect, otherwise, as pointed out by Longwalker, all loads would regulate the same, and as pointed above, groups would not open or close on demand by increasing or decreasing the powder charge and/or using powders with faster or slower burn rates, both of which are factually well established and demonstrated facts.

Group size may indeed increase somewhat because the internal ballistics are more dramatic, or it may simply be we don’t much like getting hit harder than a 6.5 ...

I personally believe that the answer is "both."

Actually I think that we agree on this. Where we likely have different conclusions is in the relative importance of each factor. If I had to quantify, I would say that I credit internal ballistics and recoil control technique for 1" to 2" at 100 yards, which is essentially irrelevant in the vast majority of hunting scenarios.

... my first shot was half inch off bullseye, not bad. Second shot, an inch off bullseye, still not bad. Third, fourth and fifth shot, roughly two to two and half inches off bullseye, hmmmmm. I’m thinking, What the hell is going on here. ...

I wholeheartedly agree that a wandering group, or no group at all, has nothing to do with internal ballistics and recoil control technique. It is 100% creditable to either defective equipment (e.g. loose scope) or, more commonly, defective or breaking down shooting technique.

Regardless, we are going to do the same things to try and overcome shot to shot dispersion.

Agreed.

I just find it more honest to say my .338 groups suck not because I am shooting a bigger rifle but because my shooting technique sucks when shooting it.

That could be the case but I do not automatically think so. I tend to think of it as our technique is sufficient to fully control a 6.5 but insufficient to fully control a .338. You will say that this is exactly your point, and I will say that there is likely an objective upper limit to what we can control.

You and I, Red Leg, provide two great test samples. In this test I shoot an exactly matched (same size, weight, action, trigger, scope, etc.) pair of Mark V Weatherby, one in .340 and one in .257. You shoot actually the same R8 rifle with different barrels (same size, action, trigger, nearly same weight, etc.). Both of us received formal training; we are life long shooters with 45+ years experience; we are conscious of the effect of technique on the outcome; and we are not overly recoil adverse. We "should" be shooting the same groups regardless of caliber. Yet we do not. Are we psychologically THAT fragile?

Shooting accuracy, from a quality rifle that’s dialed in properly (which both of mine are/were), is inherently a shooter item, the holistic side, rather than the empirical mechanical side of the equation. If there is any effect from the recoil event on that bullet exiting the barrel, it is so negligible as to be a non-factor ... my experience with the 9.3, the example of my friend and his 30-06, and any number of other times I’ve observed what I call “recoil flinch” in people, tells me that it’s the shooter 99.x% of the time, not the rifle.

I wholeheartedly agree with the psychological aspect Fastrig. My own personal conclusion is maybe a little more nuanced: the psychological aspect may be more or less prevalent depending on the shooter, and I tend to parse "shooting technique" in two distinct, successive components: "firing technique" going from the moment we shoulder the rifle to the moment the firing pin strikes, and "recoil control technique" starting when the powder ignites.

Which one is most important as to maintaining group size and group location when coming off the sled? I would again say both.

The major caveat that I think that we will agree to, is that a rifle with low recoil and substantial relative weight (say a 9 lbs 6.5 Creedmoor) is likely much more forgiving of any minute "recoil control technique" error during powder burn, than a rifle with tremendous recoil and light relative weight (say an 8 lbs .458 Lott) which, I believe, stretches most common mortal's psychological limitations during pre-ignition "firing techniques" application (knowing what is coming!), and most common mortal's physical limitations during post-ignition "recoil control techniques" applications. Again, 0.016 degree of barrel tip movement is indeed not very much

When all is said and done, a lot of this is fairly esoteric conversation. I will be the first to say that missing the buff has nothing to do with anything but the psychological state of the hunter, and that the 1" or 2" group opening and/or shift of group position I credit to internal ballistics (again, this notion of "barrel timing"), or more accurately that I credit to the control of the internal ballistics initial recoil, are utterly irrelevant to about any hunting scenario

 

[Fastrig]

View attachment 349646

I see your point, Ray B. If the rifle is made purposefully to recoil sideways, this will prove one of the two theories: POI is affected, or POI is not affected, i.e. the barrel is pointing sideways before the bullet leaves it, or the bullet leaves before the barrel points sideways.


This is the only explanation that I can come with to the very real concept of "barrel timing" for double rifles regulation. Nitro Express calibers may be the best example: extremely heavy bullet, extremely large powder charge, extremely large recoil (an 11 lbs .470 N.E. rifle launching a 500 gr bullet at 2150 fps, produces 69.3 ft/lbs of recoil at 20.1 fps - now we are talking 6.5 times the force and 2.3 times the speed of the 6.5 Creedmoor recoil), combined with slow bullet speed, i.e. longer time in the barrel.

These ought to have an effect, otherwise, as pointed out by Longwalker, all loads would regulate the same, and as pointed above, groups would not open or close on demand by increasing or decreasing the powder charge and/or using powders with faster or slower burn rates, both of which are factually well established and demonstrated facts.


I personally believe that the answer is "both."

Actually I think that we agree on this. Where we likely have different conclusions is in the relative importance of each factor. If I had to quantify, I would say that I credit internal ballistics and recoil control technique for 1" to 2" at 100 yards, which is essentially irrelevant in the vast majority of hunting scenarios.


I wholeheartedly agree that a wandering group, or no group at all, has nothing to do with internal ballistics and recoil control technique. It is 100% creditable to either defective equipment (e.g. loose scope) or, more commonly, defective or breaking down shooting technique.


Agreed.


That could be the case but I do not automatically think so. I tend to think of it as our technique is sufficient to fully control a 6.5 but insufficient to fully control a .338. You will say that this is exactly your point, and I will say that there is likely an objective upper limit to what we can control.

You and I, Red Leg, provide two great test samples. In this test I shoot an exactly matched (same size, weight, action, trigger, scope, etc.) pair of Mark V Weatherby, one in .340 and one in .257. You shoot actually the same R8 rifle with different barrels (same size, action, trigger, nearly same weight, etc.). Both of us received formal training; we are life long shooters with 45+ years experience; we are conscious of the effect of technique on the outcome; and we are not overly recoil adverse. We "should" be shooting the same groups regardless of caliber. Yet we do not. Are we psychologically THAT fragile?


I wholeheartedly agree with the psychological aspect Fastrig. My own personal conclusion is maybe a little more nuanced: the psychological aspect may be more or less prevalent depending on the shooter, and I tend to parse "shooting technique" in two distinct, successive components: "firing technique" going from the moment we shoulder the rifle to the moment the firing pin strikes, and "recoil control technique" starting when the powder ignites.

Which one is most important as to maintaining group size and group location when coming off the sled? I would again say both.

The major caveat that I think that we will agree to, is that a rifle with low recoil and substantial relative weight (say a 9 lbs 6.5 Creedmoor) is likely much more forgiving of any minute "recoil control technique" error during powder burn, than a rifle with tremendous recoil and light relative weight (say an 8 lbs .458 Lott) which, I believe, stretches most common mortal's psychological limitations during pre-ignition "firing techniques" application (knowing what is coming!), and most common mortal's physical limitations during post-ignition "recoil control techniques" applications. Again, 0.016 degree of barrel tip movement is indeed not very much

When all is said and done, a lot of this is fairly esoteric conversation. I will be the first to say that missing the buff has nothing to do with anything but the psychological state of the hunter, and that the 1" or 2" group opening and/or shift of group position I credit to internal ballistics (again, this notion of "barrel timing"), or more accurately that I credit to the control of the internal ballistics initial recoil, are utterly irrelevant to about any hunting scenario

I think this may be one of those “discussions”, kind of like CRF vs Push Feed, that will never truly be answered to everyone’s satisfaction . Enjoyed the conversation and insights immensely.

 

[Uwe Jaspersen]

I do not understand how muzzle flip can influence the POI of the shot. Target acquisition of the following shot - yes, absolutely.
Please study the super slow mo video of a pistol being fired. Observe where the bullet is when the muzzle begins to move. It is almost out of the picture by the time the slide begins to move, never mind muzzle flip

 

[One Day...]

Please study the super slow mo video of a pistol being fired. Observe where the bullet is when the muzzle begins to move. It is almost out of the picture by the time the slide begins to move, never mind muzzle flip

We all watched this video Uwe Jaspersen (see page 3) and actually it clearly shows the barrel and slide recoiling before the bullet comes out of the muzzle (see post #51). You cannot see it if you focus on the muzzle (there is no horizontal point of reference in the background to see the barrel and slide moving back), but you will see it very clearly if you look at either end of the frame where you can see the slide move back over the frame. It is between 0:10 and 0:11 if memory serves

Sadly the video also does not show a vertical point of reference in the background at the muzzle, which would have helped seeing if the muzzle jump already started. What is for sure however is that the Colt 1911 locking system is using a tilting barrel mounted on a rotating link, so in this case by definition the barrel is for sure shifting axis upward during its rearward movement, including the first 1/8" or so of movement when the bullet is still in the barrel, otherwise it could not unlock from the slide serrations as the recoil continues.

As to a discussion of the effect(s), or not, on group size and group location, of the internal ballistics recoil, please see the above two dozen posts...

PS: because the barrel unlocking tilt is mechanically controlled by the link, and therefore consistently repeatable, its effect is included in the adjustment of the pistol mechanical sights.