What twist rate for 6mm .

[range rat]

With all the barrel choices available It's just too tempting. I then started to find holes in my arsenal and suddenly found the need for a 6X45. It will be a 22 inch varmint contour. My bullet choice will be mostly 70 grain match with the occasional 55 grain being tossed in the mix. What twist rate should I get with my barrel length and bullet choice take into consideration. Now I need to make up my mind on a barrel maker. Brux, Rock Creek or Criterion ???.

[trappst]

I would say 12 twist but my experience is with the 6mm Rem. I know there are some 6x45 shooters here so hopefully they will post. The 55's won't be any problem in a 12 twist, I just don't know about 70g'ers coupled with the 6x45 velocities.

[5spd]

In my 6x45 AR with a 20" 5r groove tube and 1/10" twist, with my handloads I get .450"-910" with the 55g SP midwayusa, 65g vmax, 70g nosler BT, 80g remington SP, sierra 85 JHP game king bullets.
55g at 3100-3200 fps
65g & 70g at 3000 FPS
80g at 2800 FPS
85g at 2700 FPS

[helotaxi]

1:10 is the safe bet, but 1:12 is probably adequate for the bullets that you're looking at. 1:11 would be a safe compromise if you can find someone that makes one.

[range rat]

Thanks for the replies. I thought 11 would be perfect for my application. I'll dig around and see if I can find one.

[dperk]

PacNor has a 3 groove 11 twist 6mm.

[davidw]

+1 on the PacNor....

[sinman]

With cut rifeling you can go 1/10,1/10.5,1/11,1/12 ect, I love the twist options you can have with them. I also really like the way the interrupted fluting looks on the Brux too but that is mainly for looks.

[range rat]

Sinman
Can you hook me up with a 11 twist Brux in 6x45?