New Here: A few Ideas

[Magnum9987]

Hey, new here. I like to consider my self a firearms enthusiast. But I have a technical mind, and a few ideas have been bouncing around in my head:

If a rifle cartridge (such as a .308) where loaded with fast burning pistol powder, will its recoil be reduced? Will it have the same velocity from a shorter barrel?

If a large caliber magnum cartridge (such as the .500 magnum), where necked down to say a .45 caliber, and if the two cartridges fired a bullet of the same mass, what would the effects on velocity be? (I assume the velocity would increase)

Would adding a small rod to a direct impingement system that moved the gas block away from the mechanism, would it still have the benefit of reduced recoil but without the gases clogging up the mechanism?

If greater density of a bullet and more streamlined shape improve a bullets range, why do rifle bullets still have a small indent at the back of the bullet that increases drag? Why not make the bullet taper out (almost like the bubble shape on the rear windshield of a Corvette)?

What is the formula for changes in velocity and kinetic energy in relation to the changing mass of a bullet (if thats real funky calculus junk, feel free to warn me)?

Any and all answers are appreciated. Thanks ahead of time.

[Helix_FR]

Originally Posted by Magnum9987

Hey, new here. I like to consider my self a firearms enthusiast. But I have a technical mind, and a few ideas have been bouncing around in my head:

If a rifle cartridge (such as a .308) where loaded with fast burning pistol powder, will its recoil be reduced? Will it have the same velocity from a shorter barrel?

If greater density of a bullet and more streamlined shape improve a bullets range, why do rifle bullets still have a small indent at the back of the bullet that increases drag? Why not make the bullet taper out (almost like the bubble shape on the rear windshield of a Corvette)?

Dang Dude, you been doing some thinking. I'll get this one.
Not all rifle bullets have a small indent. There is such thing as a bullet called the boat tail These are generally for smaller and higher velocity rounds such as the .223, .243 and yes even the .308. They have a rounded tail much like the glass on a corvette that you referred to. This if for stability at higher speeds but also require a higher twist rate.

The reason concave shape on some bullets it to allow the pressures from the gasses behind the bullet to cause it to expand and engage the lands of the barrel better for greater accuracy and stability. Not all bullets have this either, many of the rounds that have been around for years and years have a flat surface on the back of the bullet. Most .308 and .45 caliber bullets are like this but not all.

If a rifle cartridge (such as a .308) where loaded with fast burning pistol powder, will its recoil be reduced? No but its pressures will be exceedingly higher along with its pressure curve. Shooting this out of a rifle is very very dangerous.
Will it have the same velocity from a shorter barrel? As if you shot it out of a rifle barrel with a proper rifle propellent? No, the pressure curve will drop much sooner and the bullet would leave sooner and then be effected by ambient conditions sooner.
3 things affect felt recoil and velocity. Bullet weight, powder charge and powder burn rate. Bullet shape have very little to do with those two things. From your descriptions above and what your suggesting is shooting lets say a 150g .308 bullet out of a pistol using pistol powder and charge? It would be equivelent to shooting a .357 magnum with using a bullet of same weight.