300 Blackout subsonic loading getting the best of me.

[Steve Donlon]

I have experimented with crimping bullets in the AR and an even crimp is very important if you use one. If your brass is not the same length you will have uneven crimps. I use an adjustable crimp die like a Lee or at least a Lee lock ring with a rubber O Ring. That way you can adjust the die down a little at a time to put a light, even crimp on your brass and it will help with velocity and accuracy. But it is more work. I don't crimp most of my bullets, only the ones with a cannelure or sometimes with slower powders where a crimp can help. And it's a separate step. It also helps to seat the bullet with a Redding Competition Seating Die so they are straight.

 

[mic2377]

Try Bullseye and Hodgdon Clays. Work down on the loads, and DO NOT double charge. It will lead to dangerous overpressure.