What has more effect on POI, muzzle velocity or recoil.

[andy52]

I would think that a semi auto pistol with all its recoil and inertia functions will have a different recoil cycle than a ridged rifle. I don't think what we see in the video is the same as what we would see with a muzzle loading rifle. That's just a theory of course since I can't prove it.

You may be correct to some degree, but in the video, the bullet has already exited the barrel well before the slide starts to move.

 

[CVA Enthusiast]

WOW I never really considered that I sight to a 6 O` Clock hold I hit center I never really considered it. I know folks that dial air speed, watch swirl, measure barometric pressures Eh I just shoot.

 

[nhmoose]

Where the sight is when the trigger breaks is the best.

 

[flatcreek]

I think the recoil is straight back and the person hold on the gun makes it go up and that gives the bullet time to leave the barrel before the muzzle rises.

 

[LME]

I think the recoil is straight back and the person hold on the gun makes it go up and that gives the bullet time to leave the barrel before the muzzle rises.

Not really! the stock is not in line with the bore and being it is lower than the barrel the barrel goes up! "For every action there is an equal reaction" !

 

[flatcreek]

If you hold the rifle upside down will the barrel go up or down?

 

[fillwa]

The person behind the trigger will have the most effect.

Bingo!

 

[LME]

If you hold the rifle upside down will the barrel go up or down?

If the rifle is held upside down the recoil will send the barrel down. Think of it like this, the stock is not straight inline with the barrel if you had the rifle shouldered and someone pushed the barrel toward you the barrel will go up due to the angle of the stock in relation to the barrel. If you do exactly the same thing except you are holding the rifle upside down it will go down. If you have a rifle with a straight stock the barrel will neither go up nor down but straight back as long as there are no other influences on the rifle.

 

[Whitworth]

The slower the round the more time it spends in the barrel to affected by the muzzle rise. At close range a slower bullet will hit above a faster round's point of aim. I've experienced this with light unmentionable wad cutter loads in handguns. YMMV

 

[Doug Fay]

Here you go, this is a slow-mo of a bullet exiting a barrel as you can see the bullet has left the barrel well before the recoill starts.

https://www.google.com/search?q=slow+mo+of+a+bullet+leaving+a+berrel&sca_esv=5261f004a4ce4d96&sxsrf=ADLYWII2VVqIZUKrvGf8asvT8BFXVumFAg:1725630442599&source=hp&ei=6gfbZrrZId3z0PEPnuyCuAs&iflsig=AL9hbdgAAAAAZtsV-hV2atc9e5nS4b7cuVTCn-0rxZEh&ved=0ahUKEwi69qqsuq6IAxXdOTQIHR62ALcQ4dUDCBk&uact=5&oq=slow+mo+of+a+bullet+leaving+a+berrel&gs_lp=Egdnd3Mtd2l6GgIYAiIkc2xvdyBtbyBvZiBhIGJ1bGxldCBsZWF2aW5nIGEgYmVycmVsMgcQIRigARgKMgcQIRigARgKMgcQIRigARgKMgUQIRifBUjxtQFQAFiisQFwAXgAkAEAmAHCAaABoRuqAQQyOC45uAEDyAEA-AEBmAImoAKzHMICERAuGIAEGLEDGNEDGIMBGMcBwgILEAAYgAQYsQMYgwHCAg4QABiABBixAxiDARiKBcICCxAuGIAEGNEDGMcBwgIFEC4YgATCAgsQLhiABBixAxiDAcICCxAuGIAEGMcBGK8BwgILEAAYgAQYsQMYiwPCAg4QABiABBixAxiDARiLA8ICCBAuGIAEGLEDwgIUEC4YgAQYsQMYgwEYqAMYmQMYiwPCAgUQABiABMICCBAAGIAEGLEDwgIOEC4YgAQYsQMYgwEY1ALCAgcQABgDGIsDwgIIEAAYgAQYiwPCAg4QLhiABBioAxiZAxiLA8ICBhAAGBYYHsICCBAAGBYYHhgPwgILEAAYgAQYhgMYigXCAggQABiABBiiBMICBRAhGKABwgIFECEYqwKYAwCSBwUyOC4xMKAH_Y0C&sclient=gws-wiz#fpstate=ive&vld=cid:d0522ee5,vid:HElQk2wEY5w,st:0

Beautifully done video!

Hi, All - Being an engineer, I wanted to throw in my 2-cents-worth on this discussion. I have to confess, this is just my theory, since I've only shot hand guns that do not have mechanisms (such as sliders) that absorb recoil. See what you think...

The recoil does, in fact, begin the moment the bullet first feels the force of the propellant, and as a result, the rear end of the barrel (face of the breech plug in my flintlock) immediately feels an equal and opposite force that tries to push the barrel and stock backwards, thus causing muzzle rise, because the pivot point in my wrist is below the center line of the barrel.

In the case of the pistol in the video, that force immediately begins pushing back on the slider, not the stock. Since the slider slides, there's not yet much recoil force on the stock. Then at some point the slider reaches the end of its travel (also having compressed the slider spring by this time). When this happens, it's the momentum and spring compression of the slider that pushes backwards on the stock and causes barrel rise. But it doesn't affect POI, because by the time this happens, the bullet has already left the barrel.

So that's how recoil begins immediately, but barrel rise doesn't for this type of gun

Now, in the case of my flintlock, or a revolver, neither of which have mechanisms to absorb recoil, the backward force on the stock begins immediately, which means muzzle rise begins immediately, thus affecting the POI.

I suspect this is a large part of the reason modern artillery have built-in recoil absorption mechanisms.

 

[andy52]

Beautifully done video!

Hi, All - Being an engineer, I wanted to throw in my 2-cents-worth on this discussion. I have to confess, this is just my theory, since I've only shot hand guns that do not have mechanisms (such as sliders) that absorb recoil. See what you think...

The recoil does, in fact, begin the moment the bullet first feels the force of the propellant, and as a result, the rear end of the barrel (face of the breech plug in my flintlock) immediately feels an equal and opposite force that tries to push the barrel and stock backwards, thus causing muzzle rise, because the pivot point in my wrist is below the center line of the barrel.

In the case of the pistol in the video, that force immediately begins pushing back on the slider, not the stock. Since the slider slides, there's not yet much recoil force on the stock. Then at some point the slider reaches the end of its travel (also having compressed the slider spring by this time). When this happens, it's the momentum and spring compression of the slider that pushes backwards on the stock and causes barrel rise. But it doesn't affect POI, because by the time this happens, the bullet has already left the barrel.

So that's how recoil begins immediately, but barrel rise doesn't for this type of gun

Now, in the case of my flintlock, or a revolver, neither of which have mechanisms to absorb recoil, the backward force on the stock begins immediately, which means muzzle rise begins immediately, thus affecting the POI.

I suspect this is a large part of the reason modern artillery have built-in recoil absorption mechanisms.

Here is a slow motion of a .357 snub. It reacts much the same as a semi. The best I can tell is that the bullets are at least 6-8 inches past the muzzle before the recoil impulse starts.

 

[Doug Fay]

Here is a slow motion of a .357 snub. It reacts much the same as a semi. The best I can tell is that the bullets are at least 6-8 inches past the muzzle before the recoil impulse starts.

It does look that way in the very slo-mo shots. However, in the shots that happen starting around 40 seconds, I held a pencil with an eraser tip up to the screen, and I think I do see a tiny bit of movement before the bullet leaves, so I still think the muzzle rise starts with the firing, but the amount of muzzle rise by the time the bullet leaves the barrel, and hence affect on the POI, will be pretty negligible. Attached is

a pic of how I tried to assess that.

 

[Greenjoytj]

Sorry, but I'm going to disagree with that.
If the bullet is no longer in the barrel - what is the firearm recoiling against?

You are forgetting about the thousands of pound of gas pressure in the barrel.
When the bullet exits all that mass weight of the gas pressure streams out of the barrel at very high velocity.
Rocket thrust is part of the recoil momentum. Mass times velocity equals momentum and only part of the momentum is absorbed by the mass weight of the firearm. What the mass weight of the firearm can't absorb is what you feel as kick.

Barrel whip is a real thing that's why shooters do a ladder test to find a powder charge weight that will place the bullet POI in with the POI of other powder charge weights so your rifle will hit to the POA on a very cold day which simulates a slightly lesser powder charge and on a very hot day that performs like a slightly larger powder charge.

Still the hands than hold the firearm and the finger that presses the trigger (incorrectly) has a much greater affect as to where the bullets will impact the target.

If your firearm could launch bullets at extremely high velocity then the POI would be below you line of sight (telescope) by the hight of the sight to the center of the bore Think laser beam from the bore and optical scope sight those 2 lines would be parallel but separate, unless sight adjustments were made to merge the beam to the line of sight at some known distance.

 

[tenngun]

Sorry, but I'm going to disagree with that.
If the bullet is no longer in the barrel - what is the firearm recoiling against?

The recoil starts as soon as the powder starts to burn
The force that movie the bullet 1/4 inch moves the breech. Not 1/4 inch because of the weight of the gun and the hold of the hand. But all action has an opposite reaction

 

[M. De Land]

WOW I never really considered that I sight to a 6 O` Clock hold I hit center I never really considered it. I know folks that dial air speed, watch swirl, measure barometric pressures Eh I just shoot.

Well once the range gets out their several hundred yards you can't consistently hit anything without accounting for and compensating for all those factors.
Elmer Keith proved accurate long range hand gun shooting is possible when these factors are adjusted for.

 

[Rifleman1776]

From my own experience, testing the 45/70 cartridge iin a Sharps rifle a 405 grain bullet at 1200 fps strikes lower at 100 yards then a 500 grain bullet at 1200 fps. This testing was done with a chronograph from the bench on targets. Not a guess or opinion just real live fire. The rifle begins recoil at the moment the bullet starts moving. Same would apply to any rifle.

I got mod zapped for making similar comments on another forum here. Talking about no-nos at all is a big no-no.

 

[Doug Fay]

You are forgetting about the thousands of pound of gas pressure in the barrel.
When the bullet exits all that mass weight of the gas pressure streams out of the barrel at very high velocity.
Rocket thrust is part of the recoil momentum. Mass times velocity equals momentum and only part of the momentum is absorbed by the mass weight of the firearm. What the mass weight of the firearm can't absorb is what you feel as kick.

Barrel whip is a real thing that's why shooter do a ladder test to find a powder charge weight that will place the bullet POI in with the POI of other powder charge weights so you rifle will hit to the POA on a very cold day which simulates a slightly lesser powder charge and on a very hot day that performs like a slightly larger powder charge.

Still the hands than hold the firearm and the finger that presses the trigger (incorrectly) has a much greater affect as to where the bullets will impact the target.

If you firearm could launch bullets at extremely high velocity then the POI would be below you line of sight (telescope) by the hight of the sight to the center of the bore Think laser beam from the bore and optical scope sight those 2 lines would be parallel but separate, unless sight adjustments were made to merge the beam to the line of sight at some known distance.

Yes - the remaining gas after the bullet leaves does produce more impulse, like a rocket engine. I don't have any stong feel for the relative magnitude of the impulse due to the bullet being expelled compared with the impulse from exhaust gas that follows. I would have guessed the impulse from the bullet is by far the greater part of it, but am not sure.

From my own experience, testing the 45/70 cartridge iin a Sharps rifle a 405 grain bullet at 1200 fps strikes lower at 100 yards then a 500 grain bullet at 1200 fps. This testing was done with a chronograph from the bench on targets. Not a guess or opinion just real live fire. The rifle begins recoil at the moment the bullet starts moving. Same would apply to any rifle.

So you're saying both shots were the same, except bullet weight, and I assume the lighter bullet was more affected by wind resistance and therefore dropped faster. Is that right?

 

[andy52]

Still the hands than hold the firearm and the finger that presses the trigger (incorrectly) has a much greater affect as to where the bullets will impact the target.

Absolutely.

 

[Phil Coffins]

Yes - the remaining gas after the bullet leaves does produce more impulse, like a rocket engine. I don't have any stong feel for the relative magnitude of the impulse due to the bullet being expelled compared with the impulse from exhaust gas that follows. I would have guessed the impulse from the bullet is by far the greater part of it, but am not sure.

So you're saying both shots were the same, except bullet weight, and I assume the lighter bullet was more affected by wind resistance and therefore dropped faster. Is that right?

No, the wind didn’t affect the point of impact. The recoil had moved the barrel less with the lighter bullet.
And my apologies for mentioning the wrong rifle to offer data to the discussion.

 

[Doug Fay]

No, the wind didn’t affect the point of impact. The recoil had moved the barrel less with the lighter bullet.
And my apologies for mentioning the wrong rifle to offer data to the discussion.

Ah, yes - hadn't thought of that, but it makes sense.