Caliber?

[Barry J]

6 ARC or 6.5 Grendel for an AR? Looks like out to 300 yards they are about the same, but the 6.5 Grendel has a larger bullet for hunting. Past 300 yards, the 6 ARC is flatter.

 

[Bolt Head]

I'd make my choice on availability of ammo/ammo components. Adding a centerfire cartridge/chambering in current times, larger than .223/5.56, the .308 Win. cartridge seems like the most logical choice given factory ammo and brass/bullet availability in almost anything that takes a large rifle primer.

Your 2 cartridge options here take small rifle/small rifle magnum primers, your biggest hurdle will be brass if you're handloading or intend to handload, so I'd base my choice on brass availability if you have to choose one of those cartridges.

 

[twinin]

Barry you pretty much summed it up. If hunting I would go with Grendel. I have one and am a big fan. I like that I can shoot whatever comes out with it. 6ARC is flatter after a while though.

308 and creed are great calibers but do not fit in AR-15

 

[Jstudz220]

6max is pretty appealing. I think personally if I was going to go with anything other than 5.56 in an AR15 6max makes the most sense.