I have an AA 6.5 Grendel and love mine. Ballistically, the SMK 123 calculates out to almost identical ballistics as the .308, but has about 1/2 the recoil.
With the wide variety of 6.5 bullets available it allows a lot of leeway for different loads.
I makes a very good 300 yard deer rifle with the right bullet, and a fair number of wild pigs have been dropped by it also.
I plan on using mine for ground squirrels, coyotes, etc. and the wide variety of bullets allows for easy changes from one to another.
I haven't seen a bolt gun in Grendel, but there are some out there, and the weakness of the AR bolts, a limiting factor in the AR platform, is gone in the bolt action rifles and will allow a much hotter round. You should easily exceed 3000 FPS with a bolt gun without problems.
I'm in Moses Lake and would be happy to let you shoot my Grendel if you are interested before you make the leap. It's in an AR platform, but it is the most enjoyable rifle I have ever shot.
Here's a graph demonstrating the Grendel vs. some .308 loads.