DuGaul
05-07-08, 13:23
I've been reading (elsewhere) and learning from folks on this forum about hand loads.
From what I gather a 75 grain BTHP bullet is right on the edge of stability in a 14.5" barrel with 1/9 twist. Ie., on a cold day it might key hole, but on a hot day it might shoot fine.
Since the rifling twist imparts a spin velocity to the bullet based on the muzzle velocity, would it be possible to make a more stable shooting load for a 75 grain bullet by loading it close to the top 5.56 velocity?
On this theory a bullet shot through a 1/7 barrel will come out with the same spin rate as a bullet shot through a 1/9 with 28% higher muzzle velocity.
Example:
1/7 x 2500 fps = 1/9 x 3214 fps
Or would it just be a waste of time, better to stick with the lower weight bullets for a 1/9 carbine?
Thanks for input!
From what I gather a 75 grain BTHP bullet is right on the edge of stability in a 14.5" barrel with 1/9 twist. Ie., on a cold day it might key hole, but on a hot day it might shoot fine.
Since the rifling twist imparts a spin velocity to the bullet based on the muzzle velocity, would it be possible to make a more stable shooting load for a 75 grain bullet by loading it close to the top 5.56 velocity?
On this theory a bullet shot through a 1/7 barrel will come out with the same spin rate as a bullet shot through a 1/9 with 28% higher muzzle velocity.
Example:
1/7 x 2500 fps = 1/9 x 3214 fps
Or would it just be a waste of time, better to stick with the lower weight bullets for a 1/9 carbine?
Thanks for input!