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View Full Version : safe barrel twist for pc bullets



git_dr1
02-02-2014, 09:56 AM
I remember reading a bit ago about someone scrapped a barrel shooting PC bullets.
If I recall correctly, it was believed the twist rate was to high in his 300 blackout.
Has the twist rate limit been established yet for shooting PC boolits?

KYShooter73
02-02-2014, 11:09 AM
That would be me. CMMG 16in carbine, 1:7 twist. I'm not going to blame it on the PC, though it is a possibility. I was using HF black, lee 312-155 COWW + 2% tin, al gas check mostly. I used some messed up hot loads, slow burning powders, compressed loads, etc. I also think I over baked my PC. Everything was supersonic. I shot 4in of the throat out in less than 500 rounds.

I have a pistol length gas port MAS barrel now, 1:8 twist. Everything seems much better. No need for hot loads to get reliable cycling. It's too cold to do much now, but I am going to try and follow Popper and BangerJim. Cast my boolits harder with copper, switch to HF red, and not over bake them. It's too cold to do my PC, but I did some tumble lube and had nice results with the copper hardened alloy at ~2000fps. I see no reason I can't repeat that with PC.

git_dr1
02-02-2014, 02:27 PM
KYShooter,

Thanks for the reply.
I have just gathered everything to start ESPC and wanted to have all my i's dotted and t's crossed before it was to late.

git_dr1