375 CheyTac Twist

[Maliclipse]

Hello,

I'm planning on only shooting solids and am very curious about what an ideal twist rate should be on the 375 CheyTac. The bullets I'm considering are the Lehigh 353s and CE 352-377s. I saw somewhere and can't find it but something about the 377 is transonic stable if shot out of a 1:9 twist. If your choices were 1:10 or 1:8 which one? Would the 1:8 spin the 350s too fast @ 3000-3150fps?

Thanks!
M

 

[Matthew488]

I went with the 1 in 7 twist for my 375 BAS to run the 400gr solids so I would think the 1 in 8 would be better for the 377gr CE. With the solids you won't have to worry about spinning to fast with the 350s. Depending on your velocity you might even get away with some jacketed 350s like the SMK.

 

[THEIS]

Hi,

There is really no downside to twisting solids fast!!
Go with a 7 or 8, completely up to you...I run 7s on pretty much everything these days (As long as monos are being used).

Sincerely,
Theis

 

[Maliclipse]

Thanks for the responses. The fear I have is a loss in velocity and too much unnecessary friction against the bore by trying to push the bullets past 3000fps.

 

[jasent]

Thanks for the responses. The fear I have is a loss in velocity and too much unnecessary friction against the bore by trying to push the bullets past 3000fps.

According to Brian Litz’s testing the speed lost from faster twist barrels is less than the es of the load being shot. Plus you won’t loose bc due to yaw. Win win imo

 

[AIAW]

Hi,

There is really no downside to twisting solids fast!!
Go with a 7 or 8, completely up to you...I run 7s on pretty much everything these days (As long as monos are being used).

Sincerely,
Theis

Exactly what Thesis said. Solids don't particularly care.

> RPM =

I went with a 1-8" on my DTA. Shot 375g Cutting Edge MTAC's amazingly.

 

[THEIS]

Hi,

They only way you will loose MV from faster twist rate is if you are using a projectile with too long of a bearing surface to begin with

The new standards in monolithics with their relatively small bearing surface in regards to OAL projectile length and weight is not going to be affected enough to even notice.

You have a better chance at missing target due to a 5m distance error than missing due to twist rate slowing down your MV too much.

Sincerely,
Theis

 

[Maliclipse]

Those are all great points. I've never shot or done load development with solids so this will be a first. I've called my distributor and changed my order to the 1-8 twist. Planning on building off a stiller 1.6" TAC408 action. Thanks for the feedback, this was very helpful.

 

[cmickles]

Robert vestal just finished up a 375 cheytac for me. I will be shooting the 377 CE solids. I went with a 1/7 t Bartlein.