So id like to build a sbr or two. I’ve read up and down about the process but I’m looking for cal recommendations. Everything I’ve read is 300blk seems useless without a can. So being a MA prisoner, i’m thinking 9mm with around an 8” barrel and .556 at 10.5”. Just looking for general input if this is the route to go and I’ll be looking to have a ffl at the freedom mill help with this also. Cheers.