Powder charge vs felt recoil?

[njc110381]

Hi all.

Today I went to the range and had a few more shots with my .416 Rigby. Things are slowly coming together and my shooting is improving a little every time. I did however notice that my home loads (400gr bullet, RL22 powder at start load) recoil harder than the factory 400gr DGS that I was using.

Does powder charge really make that much of a difference? I don't understand the reason for it? It felt like the Hornady rounds were faster but recoiled less. It just doesn't make sense!

 

[Wyatt Smith]

It would seem to that the bullet weight and and speed would would be the only things to determine recoil, but I am no expert at interior ballistics. This is a very interesting subject to me and look forward to learning more.

P.S. have you got to use the new mold yet?

 

[BB416]

Hi all.

Today I went to the range and had a few more shots with my .416 Rigby. Things are slowly coming together and my shooting is improving a little every time. I did however notice that my home loads (400gr bullet, RL22 powder at start load) recoil harder than the factory 400gr DGS that I was using.

Does powder charge really make that much of a difference? I don't understand the reason for it? It felt like the Hornady rounds were faster but recoiled less. It just doesn't make sense!

Did you chrono your loads? I’ve learned my shoulder is not an accurate chrono for my 416 loads (or any other for that matter).

 

[Kawshik Rahman]

The amount of recoil felt by the human body is determined by velocity of the bullet, weight of the bullet , and weight of your gun . A faster velocity essentially means more recoil. Heavy bullets produce more recoil than light bullets when traveling at the same speed. Lightweight guns recoil harder than heavy guns with the same ammunition type. There is one more factor we have to take into account that you have correctly thought about: the gunpowder.
Gunpowder contributes to recoil force, and it is not just that more gunpowder pushes the bullet faster and the bullet’s additional speed creates more recoil. No, the gunpowder’s weight contributes to the recoil force which the shooter feels.

 

[njc110381]

No chrono available this month. It was quite a strange experience though because a friend of mine fired the rifle first with both loads, then I did. I was expecting the recoil from the factory loads to be worse, but it actually seemed to be less. He said the same thing.

The charge in my rounds was 96gr of RL22 with a 400gr bullet. According to my Barnes data, max load is 104gr? I wouldn't expect it to chrono faster with my loads going my that data, but I suppose you never know without testing properly.

 

[JPbowhunter]

You can just knock out one of the factory projectiles and weigh the powder. You'd need to know the powder or equivalent to get any meaning from that though.

 

[mark-hunter]

Does powder charge really make that much of a difference? I don't understand the reason for it?

May I ask, if you may be aware, which of the two powders you use, burns faster?

 

[Ridgewalker]

http://www.jbmballistics.com/cgi-bin/jbmrecoil-5.1.cgi
You can plug in your data here and it will show you the approximate differences.
The energy of the recoil vs the momentum is a factor in felt recoil. Example: faster burning powders build pressure quicker than slow burning powders thus the felt recoil may be over a shorter period of time giving the impression of higher recoil even though it isn’t.
JMT on it.

 

[njc110381]

May I ask, if you may be aware, which of the two powders you use, burns faster?

I don't know what powder is used in the factory Hornady rounds. Reloder 22 is very slow though.

Interestingly, now I seem to be adapting to shooting something with this much recoil it's beginning to feel more normal to use. I think I'm ready to put a scope back on it and try to pull my groups in a little more rather than just hitting a gong. I dream of the day I can inch group it at 50m!

 

[mark-hunter]

Faster powder in smaller amount of weight, in same casing, producing same velocity of projectile of same weight will produce less recoil.

Try putting both cartridges on fine digital scale, and let see what will bee the difference.
Lets assume the casing will be same weight, -but then, if available measure also empty casings.
then we can analyse results

 

[njc110381]

Faster powder in smaller amount of weight, in same casing, producing same velocity of projectile of same weight will produce less recoil.

Try putting both cartridges on fine digital scale, and let see what will bee the difference.
Lets assume the casing will be same weight, -but then, if available measure also empty casings.
then we can analyse results

Chances are the factory load will be using less powder for sure. A grain of powder saved is profit made. They won't be giving that away if they don't have to! Time to research what they load it with.

 

[Luvthunt]

Without a chrony you do not know IF the Hornady loads were faster with less recoil. It would not be out of question that factory loads were actually slower.

 

[The Engineer]

The recoil energy is 1/2 M Vsquared. If I remember my recoil equation correctly the recoil is based on the muzzle velocity squared with the mass (M) being the bullet weight + 1.5 times the powder weight. IE: For the same muzzle velocity the weight of the powder can have a significant impact on recoil.

 

[russc]

The recoil energy is 1/2 M Vsquared. If I remember my recoil equation correctly the recoil is based on the muzzle velocity squared with the mass (M) being the bullet weight + 1.5 times the powder weight. IE: For the same muzzle velocity the weight of the powder can have a significant impact on recoil.

recoil on paper, yes, but perception and psychology is also a factor. Both the duration of the recoil impulse (fast powder vs slow powder) and the muzzle flash/bang play into the psychology. Hand someone less experienced a gun/round that has a strong muzzle flash and they'll say it recoils more than something that actually does. case and point my 7.62 tok cz52 is a flash-bang, flame-throwing powder puff but several people have said it recoils harder than my 9mm cz52. It doesn't but it sounds/looks like it does so people think it does. Actual power/recoil comparison is close enough it depends on the specific load.

 

[PHOENIX PHIL]

@njc110381

I must respectfully disagree that bullet weight and speed are the only factors in recoil, though I can't fully explain it. Without question a bullet of the same weight traveling at faster vs slower speed means more recoil. However more powder does not necessarily mean a faster bullet.

It would not be the first time that I've seen more powder NOT translate to increased velocity and in a few circumstances somewhat slower. Doesn't make sense does it?

What you have to remember is that there is an energy transfer between the energy released by igniting the powder to the bullet. With more powder there is more energy released (presuming all powder burned), but that does not necessarily mean more energy is transferred to the bullet. So where does that energy go? That's the part I haven't figured out. I just know that it wouldn't be the first time I've noticed an increase in felt recoil that isn't explained by a faster moving bullet.

This may seem crazy to you, I know it did to me when I first saw it. Buy a chronograph however and play the hand loading game long enough and you'll see it.

 

[njc110381]

P.S. have you got to use the new mold yet?

No casting done for it yet. Work has been quite busy so I haven't had the time. I'm hoping to have a go at it this weekend.

Interestingly, I have heard people say that the Hornady ammunition recoils quite hard. It could simply be the way different shooters are affected - muzzle blast vs actual recoil energy as was pointed out above. I'm going to read through my loading books and look at the charge weights, then try a powder that takes a lower charge. See where that takes me. A chronograph would be good because although I have several available to me I haven't borrowed one yet!

 

[russc]

@njc110381

I must respectfully disagree that bullet weight and speed are the only factors in recoil, though I can't fully explain it. Without question a bullet of the same weight traveling at faster vs slower speed means more recoil. However more powder does not necessarily mean a faster bullet.

It would not be the first time that I've seen more powder NOT translate to increased velocity and in a few circumstances somewhat slower. Doesn't make sense does it?

What you have to remember is that there is an energy transfer between the energy released by igniting the powder to the bullet. With more powder there is more energy released (presuming all powder burned), but that does not necessarily mean more energy is transferred to the bullet. So where does that energy go? That's the part I haven't figured out. I just know that it wouldn't be the first time I've noticed an increase in felt recoil that isn't explained by a faster moving bullet.

This may seem crazy to you, I know it did to me when I first saw it. Buy a chronograph however and play the hand loading game long enough and you'll see it.

Internal ballistics is almost magic. Lots of factors that are interrelated. It's not just how much of the powder is burned but how well, how hot, etc. Most smokeless powders are like diesel: they don't burn well at atmospheric conditions. Take an open vat of diesel and you can drop a lit match in it and the match will be smothered. put it in an engine where it's heated, pressurised, and atomized and it burns quite well. Similarly I've heard most smokeless powders are rather unspectacular when on fire in the open but do get exciting at chamber pressures.

At some point you might get the powder to burn too efficiently. That is to say that since powder burns better with heat and pressure, the more heat and pressure there is, the more is generated. What may happen is that as the powder charge goes up, the powder burns faster creating a bigger pressure spike but it's burning so hot/fast that it's spent before the bullet reaches the end of the barrel. The total area under the curve is the same (or greater) but the peak pressure is higher and sooner. Thus greater perceived recoil from the same energy being delivered faster with lackluster change in bullet velocity. Basically making the slow burning powder into a faster burning powder or loading pistol powder in a rifle round.

 

[rookhawk]

Much voodoo mentioned here. Short answer,

All other things equal, a round in same brass, same bullet, same primer: the load with the least amount of powder required to achieve the target velocity will have the least recoil.

to crystallize this: in a 470 nitro express, using RL15 instead of H4831 results in same regulation velocity with more than ten pounds less recoil!

 

[AZDAVE]

The recoil energy is 1/2 M Vsquared. If I remember my recoil equation correctly the recoil is based on the muzzle velocity squared with the mass (M) being the bullet weight + 1.5 times the powder weight. IE: For the same muzzle velocity the weight of the powder can have a significant impact on recoil.

It is the 1.5x the powder charge that people foget that really has the most effect on the felt recoil. The best example I have shot was a 8 bore with 300gr of black vs 70 gr or blue dot. same velocity, same approximate pressures, but the powder charge difference is what make one a (Are any of my fillings loose vs that wasn't bad can I shoot some more kinda recoil).

The gun fit is also something that is a big influence in to the precipitation of recoil. The other sensory perceptions that have already been mentioned of muzzle flash along with the whip of some of the light barrel kinda rifles makes some people thing that something really kicks when in fact it doesn't.

 

[The Engineer]

A couple of other areas I have found that greatly impact perceived recoil are bullet weight and stock fit.

With respect to bullet weight I find some of my high velocity smaller calibers (300 Win) have more perceived recoil than some of the DG rifles even after factoring in rifle weight into the recoil equations. To me the high velocity cartrages, even though they have less caclulated recoil. are a slap at your face and a a jab at you shoulder compared to the hard push of a DG cartridge such as the 470NE. I have found this effect is magnified by the effect of the high mounting required of some of the current scopes. The high scope mounting requires a loose check weld allowing the rifle to establish an upward velocity and forcefully impact the cheek due to dynamic overshoot. On the 300Win I had signficatly less perceived recoid when I changed from a higher mounted Swaro Z6i scope to a lower mounted Zeiss Victory HT scope even though the rifle weight is less with the Zeiss.

The above is a good lead into stock fit. A well fitted stock allow distribution of recoil without "hot spots". I have two Heym 450NE doubles that are essentially the same weight. The first one is an off the shelf 88B and the second is an 89B that was stocked to fit me. Given there are some other factors, such a where the weight is concentrated on the two rifles; but the different stock shape and fit between the two rifles makes the 89B much more pleasant to shoot. I also found the perceived recoil on the 88B was reduced signficant when I put a pad on the back of the triggger guard. The more closed grip on the 88B caused the second finger to be bashed no matter how the rifle was held and was quite painfull and just a few shots would bruise the finger. The more open grip on the 89B does not have this problem.