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Twist for .300 ultra mag

BKS

Private
Full Member
Minuteman
Apr 19, 2009
78
0
Flint Hills
I'm trying to figure out what twist I should use for a .300 ultra mag build. Correct me if I'm wrong, but twist is not only based on bullet length/weight but also on velocity. If this is true, a 180 grain bullet from a .300 ultra mag at 3350 fps can get by with a slower twist than a 180 grain bullet from a .308 at 2600 fps. Is this true?
I will be using bullets up to 210 grains (VLD and MKs). What would the slowest twist be to stabilize these bullets?
 
Re: Twist for .300 ultra mag

1-10 twist with a brake, finish at 28" to 30"

Load for us has been 210 Bergers with 91.5 grains of RL-25 but, start at 90.5 and work up to 92.0 grains max with the F215 primers .010" to .015" in the lands.

Were getting 3,250fps with this combo and driving tacks.