twist rate for 375 cheytac improved and 400 grain bullets

[huntermncb]

I was wondering if any of you guys have been shooting the cutting edge bullets 400 and up in your 375 cheytac improved. What twist rate have you guys been using with the most success. I have read and it seems most are shooting gain twists. But I have also seen 1-8 have been used as well.

 

[lazylabs]

I just researched the same thing.... If i was going specifically shoot 400s and higher i would go with a 12 to 8 (maybe 7) gain twist. I ended up deciding on a standard 10 twist. The gain in BC between 350 and 400 when factored with MV loss wasnt worth risking such a specialized twist..... My thoughts anyway. Once you go gain twist your locked into solids only....

 

[Rocky Mountain]

A 8 twist should work okay with the 400 CE I know someone using a 9 twist.

 

[Rockfish Dave]

I just researched the same thing.... If i was going specifically shoot 400s and higher i would go with a 12 to 8 (maybe 7) gain twist. [Snip]. Once you go gain twist your locked into solids only....

What are you talking about? "Locked into solids". That is just bad information you are putting out. I have been shooting gain twist barrels for the past five or six years on all my calibers and have ran everything through them with no negative effects.

Care to clarify your statement and what you are basing it on? I'd be interested to see if my experiences are a fluke.

 

[huntermncb]

Dave,
Which of the two calibers would you recommend your 338 or 375. Also
which twist would you do? Thanks

 

[Rockfish Dave]

I can only speak of my experience. I went with a 375/338 Lapua improved. I choose a twist rate that will stabilize anything up to a 350grain brass solid. The twist rate is 1:11 starting rate and 1:9.75 ending twist rate.

I wanted a fun hunting gun for flat land that will mag feed Barnes TTSX and single feed the elr fun stuff. This does it just fine.

My decision over the 338 hinged on a little longer barrel life and more terminal energy.

Post the projectile length, grain might, and muzzle velocity, and I'll post the twist rate needed at sea level. The less pressure (higher altitude) the slower the twist rate you can get away with.

In the reloading section I'm posting my load development results for the 375/338 lmi.

 

[LR3]

For what it's worth I have both a 12 and 10 twist .375 CT setup and the 10 twist is more accurate to a further distance with 350gr SMK but the velocity is higher and the barrel longer for the 10 twist.

 

[Deleted member 71114]

In a different platform -- the 375VM2

I plan on running the 414s with a 9 twist.



Cheers