What's the difference between an AR-10 and an AR-15?

[The Annoyed Man]

After doing yet some more reading, I'm thinking the 300 Blackout round would be a better choice for the AR-15. Less abuse to the BCG and equivalent terminal ballistics. Plus, if I get really brave, all I would need is the barrel and a barrel wrench (and some brave soul on the forum to hold my hand.)

If you don't plan on running a suppressor on the rifle I would go with 6.8 SPC over 300 AAC for hunting. YMMV

Exactly. And I would start with a 5.56 upper, and keep that as the standard rig, and simply buy/assemble a barreled upper in another caliber. You can swap out uppers in about 30 seconds. It's a lot easier doing that than it is trying to rebarrel a single upper whenever you want to switch.

[Wes]

Good read, go with 308! Eh, 300 black out does look nice tho. I've debated doing an sbr in it but almost thinking two 223s would be better simply for ammo type ease.

I'm kind of wishing I ordered an ar10 lower instead of the two ar15 lowers I just got tho. Options are nice to have.