Originally Posted by
Just This Once...
So maybe sometime in the future the momentum of the .50 cal going forward will equal the recoil going back towards the shooter. I guess at that point our US cousins will stop shooting .50 BMG from a big rifle.
It always was the same. It's the kinetic energy that kills you.
Imagine a ten pound gun firing a one ounce bullet at 1600 feet per second. It will recoil at ten feet per second. Momentum is 10*10 = 100 foot pounds. That's also true for the bullet 1/16 *1600 = 100 foot pounds.
Kinetic energy of gun is 1/2mv^2 (5*10^2) = 5*100 = 500 foot pounds.
Kinetic energy of bullet is also 1/2mv^2 (1/32 *1600^2) = 1/32 * 2560000 = 80,000 foot pounds. It's 160 times as much.
I don't know the actual values, this is illustrative. The recoil will also include that from the high velocity gas propelling the bullet, but I believe recoil suppression devices vent much of the gas backward - at the cost of making the gun even louder. I have never fired anything bigger than a 12 bore shotgun, and that is loud enough for me!