AR15 Upper Input

Browerka

Sergeant of the Hide
Belligerents
Minuteman
Feb 27, 2017
138
66
Virginia
I have an Olympic Arms AR15 lower that I’m looking to put an upper on for $500ish

Main use will be for predator hunting.

Who makes decent uppers that will just “plug and play?”
Thinking about a 6.5 Grendel or a 6ARC if I could find one.

Thanks for any help.