Shooting

[Jessesky]

I commented on this in another post as well. Your muzzle jumping will not affectbyour groups. The bullet has left long after recoil begins to move the gun. You cam hold the forend to reduce the jump, but that won’t affect the group, only fast follow up shots.

Look at a high speed video of a rifle firing and when the bullet leaves and you will see. Rifles move no matter what when you fire them, no matter how hard you grip. If this did effect people’s groups, no one would be able to fire accurately.

 

[Nature Boy]

The bullet has left long after recoil begins to move the gun.

Why do believe that?

 

[ford8nr]

Free recoil and a gripped forend will have slightly different POI's. Much of that has to do to reaction to the shot.
I know when I shoot my .44 Super Blackhawk my groups are much better when I let the revolver recoil. Trying to hold down on the recoil screws up my form.

 

[ford8nr]

The bullet has left long after recoil begins to move the gun

The instant the cartridge detonates and the bullet starts moving forward the rifle starts moving rearward however slight that may be. That's why follow through is so important.

 

[Picher]

I hold differently at the bench, depending on the amount of recoil expected by the cartridge and the rifle involved. When shooting an 8lb. deer rifle from the bench, I wear a PAST recoil shield on my shoulder and hold the forend down on the front bag with my left hand, but allow it to recoil rearward freely. It seems to work fine, since field shots replicate results from the bench. My .270s both shoot under 1/2 min. with handloads.

 

[Jessesky]

Why do believe that?

One millimeter of movement at the muzzle means inches at 100yards. No matter how strong you grip your rifle, it’s it’s impossible to keep it that still. Also the whole mantra of “let your rifle surprise you when you pull the trigger” to be accurate contradicts the idea of movement affecting POI, and leaves almost no premeditated recoil control.

Apart from these observations, and it being humanly impossible to keep a gun that still, I looked up the physics before. The inertia of the gun is much larger to begin “moving in time”. All in good fun

 

[PWC]

Elemental I know, but is the front rest under the wood/plastic and not the barrel?

 

[Nature Boy]

One millimeter of movement at the muzzle means inches at 100yards. No matter how strong you grip your rifle, it’s it’s impossible to keep it that still. Also the whole mantra of “let your rifle surprise you when you pull the trigger” to be accurate contradicts the idea of movement affecting POI, and leaves almost no premeditated recoil control.

Apart from these observations, and it being humanly impossible to keep a gun that still, I looked up the physics before. The inertia of the gun is much larger to begin “moving in time”. All in good fun

You made me go look up Newton’s 2nd law. I believe it supports the fact that the rifle is moving the moment force is applied to it, and that includes the time the bullet is still in the barrel

How much the shooter affects that movement and how it influences accuracy is a completely different discussion

 

[MikeInOr]

If your in basic training you had darned well better use the shooting technique you are told to. If your a civilian use the technique that works best for you. I am always open to listening to what works well for others and what the recommended technique is... but in the end I do what works best for me.

 

[Jessesky]

You made me go look up Newton’s 2nd law. I believe it supports the fact that the rifle is moving the moment force is applied to it, and that includes the time the bullet is still in the barrel

How much the shooter affects that movement and how it influences accuracy is a completely different discussion

There’s a calculation out there somewhere for this but I forget. The summary is, yes for every action there is an equal and opposite reaction. The rifle hits the shooter with as much energy as the bullet, but dispersed over a much larger area because the mass is that much more than the bullet. Because the mass is so much bigger there is more inertia and it takes longer for it to get the object (the gun) in motion.

The gun does move, but such a minute amount it’s indiscernible and does not have an effect on accuracy. And the amount it does move in that timespan from lock time to the bullet leaving the barrel is not controllable by a persons grip.

 

[Nature Boy]

And the amount it does move in that timespan from lock time to the bullet leaving the barrel is not controllable by a persons grip.

I think you’d have a mutitude of competitive shooters disagree with that statement, but “appeal to authority” is a weak argument.

I will say that in my experience, managing recoil (having the rifle track straight) has a significant and measurable impact on accuracy and group size.

 

[Jessesky]

I think you’d have a mutitude of competitive shooters disagree with that statement, but “appeal to authority” is a weak argument.

I will say that in my experience, managing recoil (having the rifle track straight) has a significant and measurable impact on accuracy and group size.

I hear what you’re saying, and I agree with appealing to authority is a weak argument. But let’s look at a lightweight match grade long range hunting rifle instead of a target rifle. These are capable (until they heat up) of the same levels of accuracy, and yet they may weigh 7lb in a very hefty cartridge. When you touch off a 338-378wea in this light rifle, it moves a considerable amount, but it’s cold bore shots can be 1/4 moa in a good rifle

 

[ford8nr]

but it’s cold bore shots can be 1/4 moa in a good rifle

7# long range, large cartridge rifle, 1/4 MOA?
As in ?
Not to be confrontational at all but ..
Have you ever shot one or just read about them.

 

[Gtscotty]

There’s a calculation out there somewhere for this but I forget. The summary is, yes for every action there is an equal and opposite reaction. The rifle hits the shooter with as much energy as the bullet, but dispersed over a much larger area because the mass is that much more than the bullet. Because the mass is so much bigger there is more inertia and it takes longer for it to get the object (the gun) in motion.

The gun does move, but such a minute amount it’s indiscernible and does not have an effect on accuracy. And the amount it does move in that timespan from lock time to the bullet leaving the barrel is not controllable by a persons grip.

You don't have the requisite information or calculations to draw these conclusions.

The pressure inside an ignited cartridge exerts a normal force on all interior surfaces.The pressure at any given time divided by the cross sectional area of the bullet base will give you the force on the bullet, divided by the cross sectional area of the inside base of the case will give you the force acting on the rifle axially through the bolt. Subtracting the friction forces from the bore, you can get the net forces on the bullet, acceleration equals Force divided by Mass. In the case of the rifle, you have a linear acceleration into the shoulder, but also an angular acceleration due to the moment arm between the force in line with the bolt, and the pivot point, your shoulder.

The acceleration of the rifle starts at the same instant as the acceleration of the bullet. On one hand, the acceleration of the rifle is far lower than the bullet due to much greater Mass, on the other hand, the motion of the rifle has a angular component and is much less constrained in direction than the bullet while it's in the barrel (relative to the barrel). Without actually doing the math on a specific rifle, load, stock geometry, etc, you can't say that the recoil induced movement of the rifle (and irregularities therin) will not have an impact on bullet POI.

Where are all these shooters that hold 0.25" groups with .338-378 in 7 lb rifles? Perhaps you could make a rifle regularly shoot like that from a rest, where forces can be uniformed, but I suspect that the increased rifle acceleration of a rig like that is going to prove my point when applied to squishy, human shoulders applying inconsistent forces to the stock.

Why do benchrest shooters use stocks that are designed to recoil straight back on specialized rests and bags?

Why do light rifles tend not to shoot as well in free recoil as heavy rifles?

Why does shoulder pressure affect POI and group size, especially with lightweight rifles?

Why do larger magnum revolvers tend to hit higher with heavier bullets than light, even when velocities are similar?

Here's an interesting article with some FEA models that suggests that recoil and recoil induced deformation affect bullet POI. Even with an 11lb 6mm PPC.

https://www.varmintal.com/alite.htm

 

[Jessesky]

7# long range, large cartridge rifle, 1/4 MOA?
As in ?
Not to be confrontational at all but ..
Have you ever shot one or just read about them.

Not taking it as confrontational, it’s discussion.

A 7lb super magnum rifle is an extreme example to make my point, but a very real one. And I know ones capable of that level of accuracy.

And yes, mine is not 7lb but I do have an 8lb 338 edge (300 ultra mag necked up) which sends 300gr at 2850fps.

 

[Jessesky]

You don't have the requisite information or calculations to draw these conclusions.

The pressure inside an ignited cartridge exerts a normal force on all interior surfaces.The pressure at any given time divided by the cross sectional area of the bullet base will give you the force on the bullet, divided by the cross sectional area of the inside base of the case will give you the force acting on the rifle axially through the bolt. Subtracting the friction forces from the bore, you can get the net forces on the bullet, acceleration equals Force divided by Mass. In the case of the rifle, you have a linear acceleration into the shoulder, but also an angular acceleration due to the moment arm between the force in line with the bolt, and the pivot point, your shoulder.

The acceleration of the rifle starts at the same instant as the acceleration of the bullet. On one hand, the acceleration of the rifle is far lower than the bullet due to much greater Mass, on the other hand, the motion of the rifle has a angular component and is much less constrained in direction than the bullet while it's in the barrel. Without actually doing the math on a specific rifle, load, stock geometry, etc, you can't say that the recoil induced movement of the rifle (and irregularities therin) will not have an impact on bullet POI.

Where are all these shooters that hold 0.25" groups with .338-378 in 7 lb rifles? Perhaps you could make a rifle regularly shoot like that from a rest, where forces can be uniformed, but I suspect that the increased rifle acceleration of a rig like that is going to prove my point when applied to squishy, human shoulders applying inconsistent forces to the stock.

Why do benchrest shooters use stocks that are designed to recoil straight back on specialized rests and bags?

Why do light rifles tend not to shoot as well in free recoil as heavy rifles?

Why do larger magnum revolvers tend to hit higher with heavier bullets than light, even when velocities are similar?

Here's an interesting article with some FEA models that suggests that recoil and recoil induced deformation affect bullet POI. Even with a 10lb 6mm PPC.

https://www.varmintal.com/alite.htm

I did not state the rifle doesn’t move at all. I said for all practical purposes it doesn’t move enough to make a difference. The OP said it was affecting his group size. And I’m stating that it isn’t causing him to have fliers. Bench rest is another story, and a story I’m not referencing.

And like in my prior post, I have LRH buddies, whether ethical or not can put a shot on a deer 800yd away with a very light rifle, or maintain 1/2 moa. No fliers like the OP mentioned

 

[Varminterror]

The gun does move, but such a minute amount it’s indiscernible and does not have an effect on accuracy. And the amount it does move in that timespan from lock time to the bullet leaving the barrel is not controllable by a persons grip.

Take a google today and learn something. It was either Frank or Jim who did a video on YouTube this last year proving should pressure influence upon muzzle velocity. Shooting free recoil yields slower bullets than holding the shoulder into the recoil.

So consider - if a guy can literally push his bullet faster by holding the rifle from recoiling out from behind the bullet, wouldn’t it stand to reason the shooter can significantly influence the bullet while traveling down the bore?

 

[Gtscotty]

I did not state the rifle doesn’t move at all. I said for all practical purposes it doesn’t move enough to make a difference. The OP said it was affecting his group size. And I’m stating that it isn’t causing him to have fliers. Bench rest is another story, and a story I’m not referencing.

And like in my prior post, I have LRH buddies, whether ethical or not can put a shot on a deer 800yd away with a very light rifle, or maintain 1/2 moa. No fliers like the OP mentioned

The OP is probably inducing movement in his Rifle with his trigger finger prior to or during the shot that is damped when he puts his support hand on the scope. I was responding to your generally applied suppositions about the effect of recoil on POI while the bullet is in the bore, which were not aimed solely at the OPs situation, and which have no basis in physics. The appeal to authority has changed to your buddies shooting deer at long range, but still isn't relative to the statements you made in earlier posts. If you're open to learning some, check out that link.

 

[ford8nr]

can put a shot on a deer 800yd away with a very light rifle, or maintain 1/2 moa. No fliers

That statement does not support your agrument that the rifle recoil doesn't affect group size or POI. It only qualifies that your buddies are very consistent shooters.

 

[ford8nr]

I know several Master Class rimfire shooters that have shot fantastic scores with basic, relatively inexpensive light rifles, scores not as high as their target rifles but higher then most are capable of. They do it sometimes just for giggles.
You could draw lots of conclusions from their performance. Really the only valid one is they are better shooters then most.

 

[ford8nr]

To the OP's issue. He's gaining extra support in his position with a fore grip yeilding better results. I would bet if he got consistant in his form/function without the fore grip his results would be similar.

Jessesky, I think were closer in opinion then apart. We disagree on whether recoil affects POI but agree on recoil ISN'T his group size issue.

 

[redneck2]

Your muzzle jumping will not affectbyour groups. The bullet has left long after recoil begins to move the gun. You cam hold the forend to reduce the jump, but that won’t affect the group, only fast follow up shots.

Not buying that. If you’re shooting a pistol, heavier bullets typically strike higher due to increased dwell time and muzzle jump.

There is a reason precision bench rest shooters let rifles free recoil

Any time I’ve tried to use a Lead Sled for zeroing a hunting gun with heavy recoil, the Impact is different from when I shoot it myself

 

[Vern Humphrey]

Makes sense. I know with pistols and the shorter barrels we consider a shot to be "made" as soon as the trigger is pulled, irrespective of recoil.

So if recoil affects POI, how could we ever hit a target? (A legitimate, sincere question, not confrontational.)

Recoil affects POI the SAME for each shot.

Take a look at a .357 revolver -- notice how high the front sight is. When you have the sights properly aligned and on target, the muzzle is pointing below the target -- but recoil brings it into alignment and allows you to hit your target.

It's the same for all guns, although not as pronounced. Your job is to not introduce things that affect the recoiling weapon, and producing variation from shot to shot.