40 cal barrel best twist rate BPCR

[beshears]

Looking at Green Mountain barrel. They have both 14.5 and 16 twist. I will be using grease groove cast of about 400 grains. Is the 14.5 to fast? lyman Snover is my go to. 40-90 Sharps Necked.

[sharps4590]

I don't have any experience with the faster twist. I do know that if the red gods smile, the atmospherics are right and I'm having one of those rare excellent days, my 40-70 Shiloh Sharps has held MOA out to 600 yards with a 410 gr. bullet. I'm just about positive it is a 1- 16 twist. Deducing from that, 1-16 is evidently plenty. I'm interested to see what others with more experience have to say.

[Gunlaker]

The 1:14.5 is definitely not too fast. I have Shiloh Sharps rifles in 1:16 and 1:14 twist. They are both very accurate. I've shot the 1:16 twist rifle more than the 1:14 twist one, but I can say that they both shoot the Saeco #740 and the BACO 409400M4 bullets very well to 600 yards.

If I were to order a new rifle it'd be with the faster twist as it has the ability to stabilize a longer bullet and hasn't seemed to hurt accuracy with shorter bullets. But either one will be good.

Chris.

[BrentD]

Looking at Green Mountain barrel. They have both 14.5 and 16 twist. I will be using grease groove cast of about 400 grains. Is the 14.5 to fast? lyman Snover is my go to. 40-90 Sharps Necked.


NO, it is not. It is perfect.

[Boz330]

I have had several 40-65 with 16 twist barrels and they work fine for 400gr bullets. I don't have any experience with a 14.5 but if you want to go heavier it should help. From your post it isn't exactly clear to me whether you are talking the 40-90 or a different 40. I have a 40-50 and it is hard to get the velocity from that short case for a 400gr boolit, theoretically a 14.5 would help.

Bob

[Lead pot]

I have two .16 ROT .40's one .40-70 and a .40-65 and one 14 ROT .40-65 and the 14 is outperforming the 16's with the same bullets from 1.4" too 1.5" long.