Home Forums Hunting & Shooting Ask The Gunwriters Reduced velocity

This for any one who understands the following statement,
( I don't ) & maybe you can explain it to me. I never was that good in physics.

In the April 2004 "Handloader", Brian Pearce article on the Rem. 300 Ultra Mag., makes this statement :
"According to a Rem. spokesperson, the advertized velocities are correct for ammunition fired in a test barrel that is fixed , or doesn't move from recoil. In other words, because a sporter wt. rifle moves back as a reaction to the bullets launch, velocity is reduced. ( There is truth to this ) "

I am not disagreeing with what the above is saying, it's just that I don't understand how recoil, can "reduce" velocity.

Can some one explain , in laymans terms, how this is ?

Chestsprings, I'm not an expert, but I'll give it a shot.

Imagine a bullet and gun that weighed the same. The gun would travel backwards at the same speed that the bullet traveled forwards (scary thought), each using 1/2 the energy of the powder.

Now imagine a gun bolted to 100 tons of concrete, which a gun in a vise essentially is. The bullet will do virtually all of the moving. The concrete would actually move a little, but scientific instruments probably couldn't measure such a tiny movement.

If the bullet in the 2cd example had a mv of 3000 fps, the bullet and gun in the 1st example would each have mv of 1500 fps.

A shoulder-mounted rifle falls between examples 1 & 2. The rifle does move back a little, and I have the scar from my first shot from a scoped rifle to prove it. <img src="/ubbthreads/images/graemlins/blush.gif" alt="" /> With some of the energy "wasted" in moving the rifle toward the shoulder, the bullet has to have a somewhat lower mv.

I never thought of this before, but it makes sense. Interesting post, thanks for bringing it up.

In one of our conversations about known but insignificant ballistics phenomena, ballistician Homer Powley put the matter in perfect perspective --

"The moon affects the trajectory but not enough to worry about."

(because the bullet is an infinitely tinier mass than the coastal waters of an ocean)

Photos by the old Winchester lab show that as far as the ultra-high-speed camera can show, the bullet is on its way -- inches beyond the muzzle -- before the rifle starts to move backward discernibly.