Gain additional velocity by shooting prone ...

[FEENIX]

Trouble maker. lol.

You are worse than me,
if anyone at the range asks me what my chronograph is I tell them it's a turbo booster... then I wait for it.

LL! I like experiments, especially when inquiring minds wants to know.

 

[GeorgeS]

Muzzle brakes cause less recoil...therefore muzzle brakes make rifles slower...muzzle brakes are bad!!

? Muzzle brakes operate after the bullet leaves the muzzle. They have no effect whatever on the bullet, recoil (before the bullet leaves the muzzle - edit), or velocity. Less recoil movement makes bullets travel faster, not slower, owing to conservation of energy. Abundant non-sequiturs here. But funny.

 

[GeorgeS]

Yep. If you weigh 500 lbs you will only need a .223 to hunt elk. The added velocity turns it into a .270. I am eating 10,000 calories a day, and not exercising so I can up the power on all my rifles.

No no no - you need to lose weight so that you can run towards the target faster, increasing the energy of the bullets you shoot, and turning your .223 into a .458 Magnum.

 

[GeorgeS]

Basic physics. There's a given amount of force created when the powder ignites. Some of that will be used to push the gun back, some to push the bullet forward. The less the gun is allowed to move, the more of that force remains to push the bullet.

Again, it's not enough to make any significant difference that I can see but the physics is sound.

Absolutely correct. Simple thought experiment: if the rifle is moving backwards at muzzle velocity, then the bullet will leave the muzzle at zero velocity and zero energy. Any lesser rifle rearward speed gradually increases bullet velocity. A rifle moving forward increases bullet velocity additively, up to light speed.

So put a light on the back of your .22 and make it an elephant gun . . . (;-)

 

[adam32]

? Muzzle brakes operate after the bullet leaves the muzzle. They have no effect whatever on the bullet, recoil, or velocity. Less recoil movement makes bullets travel faster, not slower, owing to conservation of energy. Abundant non-sequiturs here.

Recoil also happens after the bullet leaves the muzzle...hence me being facetious about muzzle brakes making bullets slower...

 

[GeorgeS]

That's great !! All we have to do to get magnum performance is to shoot everything from the prone position.

Now I will have to try and test this theory. If i get the same results i will post it. Don,t see how it makes any difference like Mud said, because the bullet has left before there is any rifle movement.

"BUT" this would also mean that a muzzle brake can add velocity to your rifle.

If he is jetting a different velocity, I would think it has more to do with the Doppler signal coming back (Reflecting) differently at ground level than bench level. I have seen velocities changed from muzzle blast with and without a blast shield in front of the screens of a chronograph.

So I will try it with a Magneto Speed, where the first thing the chronograph sees is the bullet.

I personally wont believe it until I see it.

Just Me

J E CUSTOM

There is rifle movement before the bullet leaves the muzzle; there are ample high-speed videos that establish that. Bullet transit time down the barrel is about a millisecond long - plenty of time for the rifle to move backwards a tad. In a 1911, for example, the slide is moving back before the bullet is out of the barrel. A rifle barrel is also flexing before bullet departure.

A muzzle brake can't affect the velocity of the bullet, because - unless the bullet is really loose in the barrel, and there's abundant blowby of gas - its effect is only on the gas exiting following bullet departure.

A muzzle blast effect that changes muzzle velocity as measured downrange a bit could be a result of muzzle blast affecting the alignment of the bullet with the axis of travel, effectively changing the drag component on the bullet. The bullet's center of pressure and center of mass are not coincident, so there's a rotating moment around the center of mass that would be applied to the bullet by a ground-reflected sideways force. Unlike the case with a chronograph a few meters from the muzzle, however, I doubt it would show on a magnetospeed, because it measures speed before the drag could significantly affect velocity.

A blast shield would most likely only affect the initial chronograph trigger caused by muzzle blast gases moving ahead of the bullet; the effect should be to show a lower velocity when a blast shield is absent, because the bullet would trigger the second chronograph sensor longer after the first sensor responded to the gas. That would depend on the sensitivity of the sensors to unburned powder, etc.

An empirical test would be good, however, since in theory, theory and practice are the same - but in practice, theory and practice are often very different . . .

 

[GeorgeS]

Recoil also happens after the bullet leaves the muzzle...hence me being facetious about muzzle brakes making bullets slower...

Right - I should have been clearer when I said recoil; I meant recoil before the bullet leaves the muzzle. Actually, I wonder if the diverting effect of the brake could make a bullet slower - I've never seen any study done of the effect of the "push" from muzzle gas jet force against the base of the bullet. It is moving faster than the bullet, and has solids as well as gas within it. It accelerates like mad once the bullet is out of the way.

 

[GeorgeS]

I can't believe I am commenting on this before I try to test this "theory"
But some interesting comments have came from it.

I prefer the practical application to any problem or theory.
The equal and opposite reaction is true and not theory, "But" Equal is the catch 22. The average rifle weighs 8 pounds (56,000 grains) plus the mass of the shooter. A 150 grain bullet is many times lighter. (To early to do the math before coffee) The bullet velocity will be many, many times faster than the rifle velocity and the shooters shoulder in the opposite direction. So in reality the rifle doesn't move/recoil measurably before the bullet will exits the barrel. (This is the reason
a muzzle brake must have .005 to .010 thousandths clearance all round for the bullet to pass through without touching anything.
I have never tried less than .005 thousandths for clearance so I realy cant say if it moves at all before the bullet exits.

So if we get less than 1 or 2 thousandths movement of the rifle, it doesn't make sense that velocity would change in any position. And I am not willing to restrain a rifle by placing it against a brick wall and firing it to find out.

If there is a difference in velocity, why would it not change from a lead sled to a shoulder shot. The Magneto Speed would be perfect for this test because it attaches to the rifle and moves with it.

I still think it is from ground effects from shock waves effecting the chronograph Just like the shock wave off the ground/floor that shows up in this video.

https://www.longrangehunting.com/threads/bullet-shock-wave.211219/

It is interesting to talk about this theory, but I just cant believe that the position can effect velocity that much if any.

J E CUSTOM

A Magneto Speed would be unusable for this test, because it moves with the rifle. It would show no difference whatsoever. The only chronograph that would show a change resulting from rifle movement would be one decoupled from the movement of the rifle - i.e. a ground-mounted one.

 

[GeorgeS]

A Magneto Speed would be unusable for this test, because it moves with the rifle. It would show no difference whatsoever. The only chronograph that would show a change resulting from rifle movement would be one decoupled from the moverment of the rifle - i.e. a ground-mounted one.

I can't seem to edit the misspell of movement - I keep getting an error that says that my comment contains spam. ? Edit; tried a few hours later and the edit went through; but there's no option to delete this post.

 

[NEMTHunter]

A Magneto Speed would be unusable for this test, because it moves with the rifle. It would show no difference whatsoever. The only chronograph that would show a change resulting from rifle movement would be one decoupled from the moverment of the rifle - i.e. a ground-mounted one.

Thats why the MS would work. MV is MV.

 

[GeorgeS]

Thats why the MS would work. MV is MV.

I don't follow. If you are trying to measure the velocity of the bullet relative to the muzzle, you have to have a reference frame. If the reference frame is moving with the gun, then it will show no change. For example, if a ground-mounted chronograph were moving towards the gun, it would show a higher muzzle velocity than if it were stationary. If you are trying to show that muzzle velocity decreases (relative to a fixed plane) when the gun recoils, you need a fixed plane to measure it against. The Magneto Speed is moving back with the gun. If it were moving back at 1,000 f/s, it would still show the same muzzle velocity, because the frame of reference is moving at 1,000 f/s.

Edit: I didn't do a great job above; here's the thought experiment. The gun has infinite mass, so it doesn't move. The Magneto Speed doesn't either. It records the velocity of the bullet relative to the muzzle, AND to the reference plane perpendicular to the ground. Next, the gun and Magneto Speed have zero mass, so the bullet doesn't move. The Magneto Speed and the gun do. The Magneto Speed, however, measures the velocity of the bullet relative to the muzzle as, say, 3,000 f/s - as the muzzle moves away from the bullet. But the velocity of the bullet relative to the reference plane is zero. So what we want to know - the velocity relative to the reference plane as a result of gun recoil - is NOT measured by the Magneto Speed, which shows 3,000 f/s.

 

[Capt RB]

The first movement is caused by the release of pressure on the bolt on a conventional firing pin/trigger sear/trigger. As Pressure builds it expands the vessel ie the brass to seal off then push the bullet. Then the torque induced by the bullet engaging the rifling will start the movement in a twisting motion arresting some of the rearward motion. But there are alot of things moving long before the bullet exits. The greatest amount of recoil is cause by the expanding gasses hitting the wall of atmosphere at the muzzle. This is the felt part and shows the most movement. Arresting that expanding gas with a device to divert and diffuse the amount that hits the wall at the end of the muzzle produces a reduction in reward movement.
Some things that correct some of the movement.
David Tubb's new DTR rifle uses a spring loaded bushing that holds the locking lugs to the rear against the surfaces. This helps keep the energy to drive the firing pin forward without the parasitic losses of a conventional system. Results in a faster lock time which equals a shot closer to the sight picture when the trigger was pulled.
Twisting left hand vs right hand for a right hand shooter will twist the rifle into the shooter vs away. With a rifle mounted against the shoulder and into a cheek the nut behind the trigger can reduce some of the torque induced movement. This would help in a miniscule way to use more of that enrgy being expended to move the bullet forward vs wasted energy in the recoil process.
Having a straighter case wall to grab the chamber walls will slow the rearward movement that a highly sloped case will.
These are not picking up hundreds of fps. They gain .25% here .5% there etc etc. Put them all together and you see gains that can change your DA a point or 2 for your particular rifle. Inside of 1000yds most shooters couldn't see it if you told them. For the ELR guys picking up some consistency and speed for free just for doing things to the nth degree is why they do it.
Minds are like parachutes they don't work when you don't open them. In some cases the results are quite catastrophic.

 

[Alex Wheeler]

Well, theres very conflicting data, performed without moving the gun or chony and with ammo loaded to very high precision. Free recoil vs hard hold. No difference in speed. Now 20 fps by moving a chony I can believe.

 

[NEMTHunter]

I don't follow. If you are trying to measure the velocity of the bullet relative to the muzzle, you have to have a reference frame. If the reference frame is moving with the gun, then it will show no change. For example, if a ground-mounted chronograph were moving towards the gun, it would show a higher muzzle velocity than if it were stationary. If you are trying to show that muzzle velocity decreases (relative to a fixed plane) when the gun recoils, you need a fixed plane to measure it against. The Magneto Speed is moving back with the gun. If it were moving back at 1,000 f/s, it would still show the same muzzle velocity, because the frame of reference is moving at 1,000 f/s.

Edit: I didn't do a great job above; here's the thought experiment. The gun has infinite mass, so it doesn't move. The Magneto Speed doesn't either. It records the velocity of the bullet relative to the muzzle, AND to the reference plane perpendicular to the ground. Next, the gun and Magneto Speed have zero mass, so the bullet doesn't move. The Magneto Speed and the gun do. The Magneto Speed, however, measures the velocity of the bullet relative to the muzzle as, say, 3,000 f/s - as the muzzle moves away from the bullet. But the velocity of the bullet relative to the reference plane is zero. So what we want to know - the velocity relative to the reference plane as a result of gun recoil - is NOT measured by the Magneto Speed, which shows 3,000 f/s.

In all honesty its very simple. Almost to simple. Thats why its hard to grasp when it's over thought. I am in no way saying you are stupid. I just feel you are over thinking it. I feel the point you are missing is this.

If what the video shows is true. IF! Now think on this. The FPS loss is happening IN the barrel..... Not OUT of the barrel. Thats the only place the bullet will be loosing the velocity.

So IF thats the case as its shown in the Video. Then the MS would be the best and most simple way to test IF it true or not.

Nathan @ muzzle breaks and more and the Gentlemen that makes the Terminator breaks have the best setup to test the "theory" of loss prone or from a bench. Simple reason is they can control on the there test stands how much the gun move. Simply put they can make the gun so it cant move or consistently move freely a given distance.

The true hardest part is having ammo with a ES of zero. But its not needed. just a consistent ES will do.