300BLK uses a cut down 223 case. The same bolt works with it. Overall cartridge length is the same as 223. Sooooo.... The same action length is used. The same magazines can be used. The only difference to the rifle is the chamber shape, everything else is identical.
Ugh, Mrs S is going to say “one more thing”!
I’ll trade my guns for her shoes though. I’d have twice as many. Yeah, she’s that bad.