Re: sbr in 7.62mm
I had a 6.8 that I built around a 20" bison armory barrel. Sub 1" groups at 100 yards, it was awesome. But it required it's own mags, it's own bolt, nothing was interchangable with my 5.56. I sold the 6.8 to finance a 300 blackout SBR.
There is alot more factory ammo...