Little update if your following..

Hit up the local known gunsmith, and he says he sees a lot of this with the Clymer guages and “match” chambers

He played with some guages for a few. Then a few swipes with a final reamer and now it chambers on the Go guage I have, tightly. But his match guage like butter.

Chambers a 308 like butter but 762 will chamber, just some resistance.

And rainier barrels are not guaranteed to work “reliably” on 762 ammo, per a reply from someone at rainier.



This is still all apart,will assemble and test fire soon