I’ve been looking at AR-10s and purchased a LR-308 lower without knowing the difference. I’m learning more about it every day. I really want a .338 Lapua magnum, but don’t know how my shoulder will take the recoil. I’ll probably stick with the LR-308.
If building a rifle, look for parts described as, “LR-308” or “DPMS Gen 2” compatible. Annoyingly, a large portion of DPMS parts available out there are incorrectly listed as simply AR-10 parts.