Just take your favorite AR and put a 300 BO barrel on it. BO is for Blackout, not B 0bama.
With just a barrel swap, no other parts to change, it shoots a 30 cal bullet with the ballistics of an AK or 30-30.
Yes, it would but most are fitted with a barrel for .223.
If I wanted to shoot a larger caliber on an AR platform
I’d buy an AR-10 in .308. Great caliber for deer, elk and even moose.