LOP question

[sgt_zim]

AXLE2010”. I’ve found that, for Me, LOP in a “scoped“ rifle is Not critical - anything within a standard range of 14” to 15 1’2” works fine. This is Not because I’m a great rifle shooter (average) but because of the deliberate way a scoped rifle is usually shot - you bring up to should, settle in, get steady, obtain full picture in the scope - squeeze BANG. Now, for a fast snap shot (quick mount-Fire) a better fit helps. Even with a perfect fit you can still get “Magnum Eyebrow” by either shooting Down a steep angle or Up — your eye gets much closer to the scope in both situations (plenty of videos & blood to show this). As mentioned earlier - a big bore Double Rifle & Open sights - stock fits is more important and I also think shotgun shooting from “Low Gun” stock fit is more important. I had a “Master Stock Fitter” evaluate my stock fit on an OU shotgun I shoot for Sporting Clays [an off the rack Browning] I hoped to improve my average. He said the fit was “Fine” and that I was “shooting where I looked” - he said if you are of average height 5’8” to 6’ and average build most off the rack shotguns will fit you. I was VERY disappointed because that meant All my “misses” were MY Fault. I also have 3 guns where the stocks are custom and fitted to Me….I shoot them the same as my off-the-rack guns (maybe I just can’t shoot?)

For shooting distances normal to the east half of the country, in calibers from 30-06 and below, I totally agree a perfect fit with a rifle is unnecessary. But when you step up in recoil, or need to reach out to 300 yards or further, fit starts to take on a great deal more importance.

An absolute perfect alignment of pupil to scope center at distances of 50, 100, even 200 yards really isn't a big deal. Provided the shooter doesn't flinch or jerk the trigger or something similar, POI is going to be close enough to POA that the bullet is still going to hit the boiler room. Without consistent pupil placement, that 3" group at 200 yards grows to 8 or 10" at 300 yards.

And that's to say nothing of the recoil issues that arise when you step up the 30 cal magnums and bigger. 30 ft lbs of recoil isn't a huge deal with a proper fit, but it goes from unpleasant to entirely unmanageable the more recoil there is coupled with a poor fit. BTDT.

 

[Ontario Hunter]

A wingshooting shotgun and a dangerous game rifle should both be fitted using basically the same technique: close eyes and quickly mount the gun, then open eyes. For shotgun, fire at the patterning board as soon as the gun is mounted. Don't aim the shotgun. The location of the pattern in respect of bull tells how or if the stock needs to be adjusted. I want 50/50 pattern, i.e. completely surrounding the bull. The pattern is too high and I add a slip-on pad for an extra inch. Presto! The pattern comes down to 50/50. For the DGR, the sights should line up instantly as soon as eyes open. If the rifle is scoped, the field of view should be full and total instantly when eye is opened. Both LOP and scope relief can be adjusted.

The old 3x Weaver I put on the 404 I built last summer bloodied me the first time I shot it at the range. With scope off the iron sights were perfect after conducting the instinctive test so I knew LOP was correct. Scope field of view was also perfect with instinctive mount test. Obviously that old scope just didn't have enough eye relief. So I moved it ahead a bit in the rings. That required me to pull the gun hard into my shoulder to get full field of view. Fixed the Weatherby eye issue but scope field of view is not complete when gun is quickly mounted. So I bought a new scope with 4-4.5" eye relief.

 

[Rule 303]

Here in south GA my hunting season can run from 82 to 22 degrees. I just wanted to see if it would make a difference going from a 13 1/2" on my M70 to a 14+" on a CZ since I can't try one before I buy. It sounds like there's no noticeable difference so when I find the right rifle I'll jump on it. Thanks for the replies guys yall are great

I would hazard a comment here. The shape of the heel of the recoil pad can be important with loose or bulky clothing. It needs to be rounded like a shotgun pad so as not to catch on clothing. if you have a rifle with a 13 1/2" LOP stick tape some rubber, news paper etc to it to get a14" LOP and see what feels the best for you.

 

[Mtn_Infantry]

Here in south GA my hunting season can run from 82 to 22 degrees. I just wanted to see if it would make a difference going from a 13 1/2" on my M70 to a 14+" on a CZ since I can't try one before I buy. It sounds like there's no noticeable difference so when I find the right rifle I'll jump on it. Thanks for the replies guys yall are great

Unless the 13.5” feels like you’re stretching when wearing all your layers you should be good to go. If it does, you can always have it shortened.

 

[HankBuck]

For shooting distances normal to the east half of the country, in calibers from 30-06 and below, I totally agree a perfect fit with a rifle is unnecessary. But when you step up in recoil, or need to reach out to 300 yards or further, fit starts to take on a great deal more importance.

An absolute perfect alignment of pupil to scope center at distances of 50, 100, even 200 yards really isn't a big deal. Provided the shooter doesn't flinch or jerk the trigger or something similar, POI is going to be close enough to POA that the bullet is still going to hit the boiler room. Without consistent pupil placement, that 3" group at 200 yards grows to 8 or 10" at 300 yards.

And that's to say nothing of the recoil issues that arise when you step up the 30 cal magnums and bigger. 30 ft lbs of recoil isn't a huge deal with a proper fit, but it goes from unpleasant to entirely unmanageable the more recoil there is coupled with a poor fit. BTDT.

SGT Zim: I like your logic - makes sense and think it can apply in some situations. I’m not sure if moving from a .30-06 to .375 H&H changes how I want my rifle to fit and certainly don’t think my “eye alignment” on my scope changes based on minor stock fitting measurements (I don’t want to get ‘Scope Smacked’ with any caliber). I get my Full Scope Sight Picture regardless of how my rifle is mounted (Bench, off hand, sitting, or Prone) and all of those different shooting/body positions slightly change where that stock is positioned against your shoulder/body - requiring slight adjustments be made To properly align my eye to scope or sight. No stock will Fit “exactly” the same in every different shooting position - some body adjustments are always made. While I agree there is never a downside to a properly fitted stock - I don’t believe there is such thing as a “prefect stock fit”, even things as minor as clothing thickness causes slight changes in LOP but those are all easily adapted too as you line up your eye for that “Familiar-sight-picture” you’ve become accustomed to seeing before “pull”. Lastly, I’m gonna question (because I don’t know) why shooting a 3” group at 200 yrds could deteriorate to a 8”-10” group at 300 yrds - all else being the SAME - because you eye alignment with scope was not perfect? If your eye alignment was Not perfect at 200 yrds and 3” group was the result…then the same Eye Alignment for a 300 yrd shot should be a mathematical calculation and result in a 4 1/2” group (increased distance by 50% = increased group size x 50%. 3x1.5=4.5. But I must admit I am NOT qualified to make this assertion because neither my Bench Rest Shooting abilities nor my Math skills are very good.

 

[Ontario Hunter]

SGT Zim: I like your logic - makes sense and think it can apply in some situations. I’m not sure if moving from a .30-06 to .375 H&H changes how I want my rifle to fit and certainly don’t think my “eye alignment” on my scope changes based on minor stock fitting measurements (I don’t want to get ‘Scope Smacked’ with any caliber). I get my Full Scope Sight Picture regardless of how my rifle is mounted (Bench, off hand, sitting, or Prone) and all of those different shooting/body positions slightly change where that stock is positioned against your shoulder/body - requiring slight adjustments be made To properly align my eye to scope or sight. No stock will Fit “exactly” the same in every different shooting position - some body adjustments are always made. While I agree there is never a downside to a properly fitted stock - I don’t believe there is such thing as a “prefect stock fit”, even things as minor as clothing thickness causes slight changes in LOP but those are all easily adapted too as you line up your eye for that “Familiar-sight-picture” you’ve become accustomed to seeing before “pull”. Lastly, I’m gonna question (because I don’t know) why shooting a 3” group at 200 yrds could deteriorate to a 8”-10” group at 300 yrds - all else being the SAME - because you eye alignment with scope was not perfect? If your eye alignment was Not perfect at 200 yrds and 3” group was the result…then the same Eye Alignment for a 300 yrd shot should be a mathematical calculation and result in a 4 1/2” group (increased distance by 50% = increased group size x 50%. 3x1.5=4.5. But I must admit I am NOT qualified to make this assertion because neither my Bench Rest Shooting abilities nor my Math skills are very good.

Using geometry I calculate the group at 300 yards should be 2.25" x 2 = 4.5". According to my calculations, the angle of spread of 3" group from bench to 200 yard target is 0.86 degrees. Halve that angle to make a right triangle with adjacent side = 300 yards. Tan of 0.43 degrees x 300 = 1/2 of group diameter at 300 yards. Maybe my math skills are no better than yours.

 

[HankBuck]

Using geometry I calculate the group at 300 yards should be 2.25" x 2 = 4.5". According to my calculations, the angle of spread of 3" group from bench to 200 yard target is 0.86 degrees. Halve that angle to make a right triangle with adjacent side = 300 yards. Tan of 0.43 degrees x 300 = 1/2 of group diameter at 300 yards. Maybe my math skills are no better than yours.

ONTARIO: It’s not nice to write in a language that I can’t even understand!! SO, to simplify things - do you agree the variance from 200 to 300 yrds should only be about a 50% increase in group size?

 

[sgt_zim]

SGT Zim: I like your logic - makes sense and think it can apply in some situations. I’m not sure if moving from a .30-06 to .375 H&H changes how I want my rifle to fit and certainly don’t think my “eye alignment” on my scope changes based on minor stock fitting measurements (I don’t want to get ‘Scope Smacked’ with any caliber). I get my Full Scope Sight Picture regardless of how my rifle is mounted (Bench, off hand, sitting, or Prone) and all of those different shooting/body positions slightly change where that stock is positioned against your shoulder/body - requiring slight adjustments be made To properly align my eye to scope or sight. No stock will Fit “exactly” the same in every different shooting position - some body adjustments are always made. While I agree there is never a downside to a properly fitted stock - I don’t believe there is such thing as a “prefect stock fit”, even things as minor as clothing thickness causes slight changes in LOP but those are all easily adapted too as you line up your eye for that “Familiar-sight-picture” you’ve become accustomed to seeing before “pull”. Lastly, I’m gonna question (because I don’t know) why shooting a 3” group at 200 yrds could deteriorate to a 8”-10” group at 300 yrds - all else being the SAME - because you eye alignment with scope was not perfect? If your eye alignment was Not perfect at 200 yrds and 3” group was the result…then the same Eye Alignment for a 300 yrd shot should be a mathematical calculation and result in a 4 1/2” group (increased distance by 50% = increased group size x 50%. 3x1.5=4.5. But I must admit I am NOT qualified to make this assertion because neither my Bench Rest Shooting abilities nor my Math skills are very good.

In the case of the pupil aligning with the center of the scope, I should have been more specific - comb height is the critical piece of "fit" here, not necessarily LOP. Just increasing the comb height on my 308 took me from about a 10-12" group at 300 yards down to 3".

As I alluded to earlier in this thread, adding an inch to LOP and a little over a half inch to comb height changed the felt recoil dramatically on my 404 Jeff. I can't say which may have improved the shooting experience more for the better, but combined, they gave me a big medium which I can happily shoot now.

 

[sgt_zim]

ONTARIO: It’s not nice to write in a language that I can’t even understand!! SO, to simplify things - do you agree the variance from 200 to 300 yrds should only be about a 50% increase in group size?

I agree it should be. But if the center line of the scope and the comb height are very far apart, the shooter simply won't consistently line up his pupil with the centerline of the scope. Groups will be erratic/unpredictable.

It's no different than practicing shooting free throws in basketball. Perform the exact same mechanics every time and the results will be predictably good. It isn't impossible to be a consistent shooter if stock fit is poor, but it will take quite a lot more practice. The easiest solution is to add height to the comb.

 

[Ontario Hunter]

I agree it should be. But if the center line of the scope and the comb height are very far apart, the shooter simply won't consistently line up his pupil with the centerline of the scope. Groups will be erratic/unpredictable.

It's no different than practicing shooting free throws in basketball. Perform the exact same mechanics every time and the results will be predictably good. It isn't impossible to be a consistent shooter if stock fit is poor, but it will take quite a lot more practice. The easiest solution is to add height to the comb.

Improper pupil centerline alignment will only  maybe be a factor at extended distances. For dangerous game rifles the range is too close to be seriously affected. However, for those rifles fast acquisition is paramount for obvious reasons. Adjusting ring height, eye relief, height of comb, cast, and length of pull each can improve a scope's quick target acquisition.

If the shooter performs the quick acquisition test mounting the rifle eyes closed and when opening them is looking up the barrel (i.e. front sight bead is above the V in rear sight blade), then the length of pull is too short. Add a slip-on recoil pad. If the bead is buried below the V then LOP may be too long. Bead right or left, then cast may need adjustment (if possible). I am of the opinion that a DGR that acquires instantly is much more important than a rifle that looks "classy." Getting on a charging angry one ton beast quickly and accurately is absolutely paramount, especially follow up shots fired from rifles with extraordinary recoil.

 

[Rule 303]

Sgt Zim answered the mathematical question. I was just going to put it a slightly different way in that SZ was talking about the each time you go to shoot you pupil will be in a slightly different place each time. Hence the math's go out the door.

Some very good knowledge and information in this thread.

 

[HankBuck]

Sgt Zim answered the mathematical question. I was just going to put it a slightly different way in that SZ was talking about the each time you go to shoot you pupil will be in a slightly different place each time. Hence the math's go out the door.

Some very good knowledge and information in this thread.

RULE303: there is so much “Good knowledge and information” in this thread that I’m shocked that Anybody ever Hits ANYTHING without a PHD in physics and Philosophy…shooting just can’t be this complicated otherwise I would have Never had the need to visit a Taxidermist. We do ALL love to over analyze and over think things…Me included

 

[Rule 303]

HankBuck, that makes at least 2 of us.

 

[sgt_zim]

Sgt Zim answered the mathematical question. I was just going to put it a slightly different way in that SZ was talking about the each time you go to shoot you pupil will be in a slightly different place each time. Hence the math's go out the door.

Some very good knowledge and information in this thread.

Like Ontario and I have both said - at ordinary hunting distances (say 200 yards or closer), a perfect cheek weld is a nice-to-have, but it isn't nearly critical to putting meat in the freezer.

For my own self, 300 yards is where my groups opened up in the past due to poor cheek weld/comb too low. If my face didn't fit my rifle, the only way I'm ringing steel at 1000 yards is by pure, dumb luck.

When pulling the trigger on game animals, 400-ish yards is my self-imposed limit. Errors begin to compound themselves out in that territory, and it's something I'm just not willing to risk.

 

[Rule 303]

400ish is my self imposed limit and then I need a bloody good rest tor the forehand. Normally I try to be prone at this range.

You may be surprised at how many, when learning to shoot go from 5 shots into 25mm at 25 mts to 200 to 300mm at 100 mts. Once you explain the math's to them and reiterate the aiming principles they go back to 100mm at 100mts. Mind you that was with peep sights not a scope.