6.5 prc heavy bullet twist rate

[TriggerTime426]

I'm lookin into what twist rate I should get for a 6.5 prc barrel that I will probably be shooting the berger 156 eol for big game, it's between a 8, 7.5, and a 7 twist. Seeing if anyone has any experience with this particular bullet (the barrel will be 25-26 in)

 

[EricRF]

I called Berger and they said 1:8 usually works fine, but 1:7.75 or 1:7.5 is ideal. I still went with a 1:7 twist for my 6.5 PRC that is being built for better stability with the monometals in addition to the Berger. The problem that you might run into is too fast of RPMs if you jack up velocity. I read that you want to keep it under 300,000 RPMs. Formula Being Velocity x 720 / twist rate. So at 3000fps, your RPMs would be 308,000. A little above that general rule of thumb, but I think it should be ok. Browning is now chambering most of their 6.5s in 1:7 twists too.

 

[ruby76]

Yes my browning hells canyon long range has the 1:7 twist. I have some 156 bergers loaded in ADG brass with H1000 to test out.

 

[TriggerTime426]

Thanks for the info lemme no how those 156s shoot...I have a target rifle in 6.5 prc with 8 twist and it shoots the 147 eld very well also with h1000....might be best going in between and goin with the 7.5 twist

 

[JAYgs8163]

I'm building mine now with a Proof 1/7.5 and having chamber cut specifically for the longer bullets. Primarily the 156 Berger. Should have it done in a few weeks.

 

[Jud96]

1-7.5 is about perfect for a 6.5 PRC running the 156 Berger's. Not too fast to worry about over-spinning bullets at high RPMs, but fast enough for the 150-156s.

 

[TriggerTime426]

7.5 is what I'll go with then, thank for the input guys

 

[lancetkenyon]

I run a 1:7.5" twist in my 26" & 20" 6.5SSs. Both are crazy accurate with the 156 Berger. And 150 SMK, and 144 Hyb.

 

[excaliber]

Would that 7.5 twist work equally as well with the 140-147 grainers too?

 

[Shane431]

Would that 7.5 twist work equally as well with the 140-147 grainers too?

Yes!