Re: what bullet
Hey Tex,
I have a 300 Blackout that I shoot sub-sonic. I have been using 220gr SMK's. I have done more research, and have found out that the 220 round nose will work better for sub-sonic applications. They are also much cheaper than the SMK's. I haven't tried them yet, but think they should work well.
Jim
PS Mine is a 7.5 twist.