oz_lowrider
Member
With my SAKO 223 why is it that a 1:8 twist will stabilise bullets from 55gn to 90gn when a 1:12 doesn't stabilise anything above 60gn.
With my SAKO 223 why is it that a 1:8 twist will stabilise bullets from 55gn to 90gn when a 1:12 doesn't stabilise anything above 60gn.
needs more what? This is almost all that was needed.a longer cylinder
Street Terms?
Condensed version.
1.) It takes less twist to stabilize a given bullet at high velocity than at low velocity.
2.) At the same velocity in the same caliber, longer (pointed) bullets require faster twist rates than shorter (round nose) bullets of the same weight.
3.) Heavier bullets require faster twist rates than lighter bullets of the same shape.
Nice effortAs an example (only), let's say all bullets need to spin at X rpm to stabilize. Short light bullets will get down the tube quickly at say 3000 FPS on exit, so out of a 24 inch barrel, they need a 1:12 twist. A heavier slower accelerating bullet will only exit at 2/3 the speed, so it needs 30% faster twist to get the same rotation rate, and because it's a longer cylinder, it may need even more? There are other factors, but that's the simple idea.
Name them.Brocluno made some valid points
1.) It takes less twist to stabilize a given bullet at high velocity than at low velocity.
2.) At the same velocity in the same caliber, longer (pointed) bullets require faster twist rates than shorter (round nose) bullets of the same weight.
3.) Heavier bullets require faster twist rates than lighter bullets of the same shape.
why is it that a 1:8 twist will stabilize bullets from 55gn to 90gn when a 1:12 doesn't stabilize anything above 60gn