300 blackout

I use Outdoortrader, just would like extra network on here, i am not too sure how different this is. i am located in atlanta. I have a 300 blackout ARP looking to sell or trade, sights are installed, brand new, never fired.

BCM factory upper reciever Ballistic Advantage 9” 300blk barrel SLR 8.3 ion lite rail AAC 3 prong non mount +/- 60 rounds through it $400obo Trade for exps or toward mini acog or Aimpoint mini

All I am new to the 300 Blackout reloading and when seating 110gr FB bullets to an OAL of 2.1 seems there is just not much bullet for the case to purchase cases are trimmed to 1.35 to 1.36. Is anyone loading these using a factory crimp die to tighten them up a bit. So far all have shot fine but...

Which combo do you run? I run: - SBR 9inch AAC barrel with Carbine Length and suppressor with T3 buffer - Rifle 16 AAC barrel with rifle length and suppressor with H2 buffer - Break Barrel 16 inch R5 barrel with suppressor.