I started getting parts for an 80% AR 308 build a few years ago, but then kind of stalled when the plandemic started & I concentrated on finishing AR15 builds. A couple months ago I decided I'd start in on the 308 build again. BCG's were one of the hardest things to find, I didn't find anything I really wanted, finally settled on this one.
https://www.sportsmansguide.com/product/index/losok-custom-arms-ar-10-semi-auto-bolt-carrier-group-nitrite-finish?a=2241595
Don't know if it's any good, but It'll have to do for now at least.