Effects of Recoil on Accuracy

[M-Tecs]

Something lighter is always easier to control than something heavier, and in this case we are talking about recoil. It just so happens that a 'heavier' gun recoils less - that is simple physics.

Recoil is just one component of a long list of influences that effects practical accuracy. Additional mass can overcome poor technique but that is not always the case. Prime example is the various offhand shooting competition. Depending on what the rules allow max weight may be the best choice but too heavy for the shooter the additional mass become a liability.

If recoil is significantly reducing your accuracy you need to improve your technique.

[M-Tecs]

I am saying, to use your caliber for example, a 16lb 375 H&H will have 'lighter recoil' than a 8lb 375 H&H. The 16lb one will be easier to control the recoil, thereby easier to get better groups.

My 7 1/2 pound 6mm Dasher is a sub 3/8 MOA rifle. My 12 to 14 pound 6mm Dashers are sub 3/8" MOA rifles. Due to the mass I can shoot the heavy ones offhand better but from the bench they are equal. I did build a 22 pound Dasher for a friend. That is basically impossible to shoot offhand. Again if recoil is solely the reason for reduced accuracy you have an issue with your technique.

[newton]

If you actually reduce the amount of barrel movement before the bullet leaves the muzzle you will change point of impact.

Change point of impact from where?

[newton]

I think robg is close to the truth on this topic, particularly with reference to "triggers".

Realize the trigger is pulled well before (in relation to the barrel time from primer ignition to muzzle exit) the primer is struck. The trigger is pulled and the hammer/striker/firing pin all have to bang on the primer before it goes bang.......that means there is movement of/in the rifle prior to the cartridge firing. Perhaps imperceptible when shooting from unsupported positions but it's still there. Given an equal trigger pull there is a lot more potential with the lighter weight rifle for some movement of the rifle during the pulling/pressing of the trigger and the fall of the hammer/striker/firing pin. The use of a more solid shooting position helps considerably........."hold hard, shoot straight".......

Then there is always; "well, I had a perfect aim just before I close my eyes and yanked the trigger......." Then if they all went into one hole all the time this probably wouldn't be the fun it is........

Very true. It would be boring....or would it.....if all the bullets went into the same hole? To some it would be, for me not until I had done so with every gun and caliber there is. I figure there is enough of both around to keep me preoccupied till I die.

I do agree that recoil is just one aspect of accuracy. But it’s that aspect I had never truly realized meant as much as it does. I always just chalked it up to being able to control flinching. Not until I realized that the barrel can move so much(or little, depending on how you view it) did I start understanding what recoil means.

I have only scraped the surface as far as I’m concerned. I just hope that one guy looking to figure out why his groups are so large when he has tried everything else but controlong the recoil of the gun for that few milliseconds the bullet is still in the barrel, sees this thread and tries something new.

[newton]

Recoil is just one component of a long list of influences that effects practical accuracy. Additional mass can overcome poor technique but that is not always the case. Prime example is the various offhand shooting competition. Depending on what the rules allow max weight may be the best choice but too heavy for the shooter the additional mass become a liability.

If recoil is significantly reducing your accuracy you need to improve your technique.

I agree, but it’s the one aspect I’m trying to focus on with this thread. There are a lot of different factors that play in with accuracy, but I want to focus on recoil and it’s effect on the bullet while still in the barrel.

[newton]

My 7 1/2 pound 6mm Dasher is a sub 3/8 MOA rifle. My 12 to 14 pound 6mm Dashers are sub 3/8" MOA rifles. Due to the mass I can shoot the heavy ones offhand better but from the bench they are equal. I did build a 22 pound Dasher for a friend. That is basically impossible to shoot offhand. Again if recoil is solely the reason for reduced accuracy you have an issue with your technique.

Why can’t you shoot sub 1/4” groups? Is it impossible?

Why is it possible for rail guns to consistently shoot sub 1/4”, 10 shot groups, at 200 yards? I’ll give you a clue.... .......they control recoil.

[popper]

Recoil energy is dissipated in the mass of the gun. More mass, less movement. The stock pivots around the shoulder (or arm) and the barrel moves up. Longer barrel - less movement - weight. Stock angle makes it worse. Torque from rifling twists the gun. Then add the human part.

[newton]

Oh, I almost forgot. I DO have a problem with my technique. That is the whole point of this. My problem is I was trying to just let recoil do it’s thing instead of controlling it.

Now that I know I need to control it, I can work on other aspects of shooting to dial the accuracy down even more.

[newton]

Recoil energy is dissipated in the mass of the gun. More mass, less movement. The stock pivots around the shoulder (or arm) and the barrel moves up. Longer barrel - less movement - weight. Stock angle makes it worse. Torque from rifling twists the gun. Then add the human part.

Bingo. I would make one comment though, recoil energy is actually transferred through the mass of the gun. Some is absorbed, but most is transferred.

If you ever got bored, pull up one of those recoil calculators. Enter in the normal data, and then start increasing the weight of the gun till recoil is zero. Pretty interesting results.

[JBinMN]

Something to share regarding the topic that some may be interested in, if they have not come across it before:
https://archive.org/details/Hatchers_Notebook/page/n260

Hatchers Notebook

By Maj. Gen. J. Hatcher

Notably, the following chapters:

Chapter XI

Block that Kick - Some Observations on Recoil

Starts on page 253 of the book, but page 262 of the link.


And...

Chapter XII

The Theory of Recoil

Starts on page 279 of the book, but page 288 of the link.

Enjoy! if ya like.

[Traffer]

I learned a lot by watching Mark and Sam videos. Here is the most recent one posted on youtube (actually a rerun) I think Mark has a gift of being able to explain these things with a simple logical perspective...

[JBinMN]

Recoil energy is dissipated in the mass of the gun. More mass, less movement. The stock pivots around the shoulder (or arm) and the barrel moves up. Longer barrel - less movement - weight. Stock angle makes it worse. Torque from rifling twists the gun. Then add the human part.

Oh, I almost forgot. I DO have a problem with my technique. That is the whole point of this. My problem is I was trying to just let recoil do it’s thing instead of controlling it.

Now that I know I need to control it, I can work on other aspects of shooting to dial the accuracy down even more.

Which is why the shooting sling I mentioned earlier is used. It increases the mass of the rifle, by the mass of whatever part of the human body it is connected to. Meaning, that if you have the rifle well fastened to more of the shooter, then more of the mass is able to deal with the effects of the recoil. If the rifle weights 8# & your slinged arm to rifle weighs an additional 8#, plus the "bracing" effect using the sling, then the combined is 16#. Spreading the the felt recoil as well as reducing its' effect, while keeping the rifle in relatively the same position as well.

I will bow out now & let the rest of you continue. I seem to be focusing on one part of the recoil subject, while it seems the rest of ya'll are on another. Better to just "shut up & listen(read)", I reckon. Sometimes, folks say that is "the best way to learn.", (but actually doing something & gaining experience is a good way to learn too, IMO.)
LOL

HAve fun!

[M-Tecs]

Why can’t you shoot sub 1/4” groups? Is it impossible?

Why is it possible for rail guns to consistently shoot sub 1/4”, 10 shot groups, at 200 yards? I’ll give you a clue.... .......they control recoil.

Rail guns remove all shooter induced factors other the wind reading ability and the ability to produce as humanely perfect ammo as possible. Recoil induced errors are not a factor unless you have a really poorly designed rail gun. Some good pics of rail guns here. http://bulletin.accurateshooter.com/tag/rail-gun/

As to me personally shooting sub 1/4 MOA groups I have done so on numerous times, however, unless I can do it on demand I don't claim that as what I am capable of. Same for the rifles I build. I am mostly interested in F Class and 1,000 yard NRA Highpower competition. Those games are won and lost mostly on wind reading ability.

For F Class and 1,000 NRA Highpower the extreme loading techniques that are a must for benchrest are mostly a waste of time or not feasible.

[RED BEAR]

I am not buying that bad technique affects lighter recoiling guns less ether bad shooting habits are bad shooting habits. And the fact hat a heavier bullet may impact higher than a lighter one is here nor there . Its about the zero and knowing what you are shooting.

[country gent]

A tight sing can affect the rifles zero and grouping. Another induced issue with the sling is if over the bicep or muscle a "pulse beat" can be transmitted to the rifle thru it. When a tight sling is used harmonics are affected.

For what the OP is wanting a second stock fitted to the rifle and tuned with 3-5 lbs of weight added maintaining balance. Basically a hunting carry stock and a "shooting" stock that adds weight. The second stock could have a channel routed out in the forearm for 2-3 lbs of lead shot mixed with epoxy and a couple holes drilled in buttstock for another 3-4lds or what it takes to balance the rifle. Both stocks bedded to the barreled action and would only be a couple screw and torqueing to swap. The weights could be fitted and be removeable themselves even.

[M-Tecs]

I am not buying that bad technique affects lighter recoiling guns less ether bad shooting habits are bad shooting habits. And the fact hat a heavier bullet may impact higher than a lighter one is here nor there . Its about the zero and knowing what you are shooting.

From personal experience in shooting NRA Highpower with M14 and AR15 type rifles of the same weight bad technique has a lesser effect on the AR. This really shows when building your position for both the sitting and prone rapids. To shoot cleans with the M14 I needed to have a very good position. With the AR I can shoot cleans with a lesser postion.

Same for shooting of the bench. If I vary my hold technique I see greater effect as the recoil goes up. Anything the you do the changes the amount of movement the firearm has before the bullet exits the barrels will have an effect.

[rking22]

I see this thread as discussing an aspect of “mechanical accuracy”, barrel movement while the projectile is still in the barrel. If you want to use a 50 BMG to test with, you need 2 rifles the same other than weight, that is the OPs variable. My take is a rifle with a better moment of inertia will shoot better than another identical with less. Same weight different distribution. A heavy barrel will move with slower acceleration, movement than a lighter. A shorter barrel gets the bullet clear of the barrel quicker. A short heavy barrel helps reduces movement before exit better than a longer and/or lighter barrel in the same overall weight rifle. If you put a bloop type on that short heavy barrel with even more mass farther to the front, even better, it just has to be clear of the bullet. A hard recoiling light hunting rifle will shoot better bench groups, and Maybe even be close when shot from a field position, if you hold on to the fore end. A dedicated target rifle in 222 or equil is a different animal.

[bmortell]

maybe recoil starting motion helps the variations manifest since static friction has already been broke, so more recoil is practically less mass?

like say a 100 pound block is sitting on the ground and you tap it with a tiny hammer and you cant measure a movement since the tap wasn't enough to overcome the friction.

if the 100 pound block was sliding 10mph and you tap it on the side you could probably measure a small sideways movement

[dave roelle]

A large part of your answer can be found in a "free body diagram"

study this approach and i believe you will put a bunch of the pieces of the puzzle together that have been mentioned previously

stock design is a significant part of the study, your FBD will help you see what you are imagining

Dave

[popper]

Some is absorbed, but most is transferred. Kinda. Energy is required to get the gun moving - more mass more energy. Momentum of the rifle is transferred to your shoulder and barrel rise - thus the wrapped sling. Momentum is mass*fps so more mass, less fps at your shoulder and the fps is what hurts. The 'banger' holding of a pistol actually may aid in 'back on target' as motion is horizontal vs both. Before the brake on the tommy gun, GIs would let the sling hang from the front and step on the strap to reduce barrel rise. And if you used a wrapped sling, changing drum/mag was slow.