Don't have either at this point, but the 6.5 Grendel eats the 6.8's lunch pretty much across the board for varmints, medium game, and especially as a long-range cartridge. It fits the same platforms as well. A fast-twist .223 also surpasses the 6.8 for a lot of purposes, I think, and has mountains of available rifles and cheap ammo and components.
All that doesn't mean the 6.8 isn't worth owning and using, just that there's better stuff out there. It probably doesn't help that the 6.8 is a stubby little number that looks kind of dumpy compared to the sexy Grendel.
Another issue for me is that 6.8 brass is an odd duck, and given what we've been through the last few years, feeding one could become problematic in a pinch.
I was looking debating on what cartridge I wanted a compact CZ 527 chambered in for a light weight deer hunting rifle. Cartridges I considered included the 6MM PPC, 6.5 Grendel, 6.8 SPC and the simple 7.62 x 39. While all are good choices and only one or to rifles to be put together I went with the 7.62x39 for simplicity and the Grendel for all around top performance at all distances I would consider shooting a deer.
The Grendel is the rifle I am most passionate about truth be told. 6.8 SPC is a fine choice also. Grendel is simply better in my eyes.
