Lovely, I suggest you true / lap the upper receiver face on both and glue the barrels in with Loctite 609>
All mine I have done this to, shoot more factory ammo, with more consistently tighter grouping.
I have so much faith in this, that I do it to ALL my uppers.
As an example... this is a factory PSA 308 upper with a FN CHF CL barrel at 100yds..10rds Hornady 155gr Amer. Gunner.
I don't shoot like this every day , but...
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And my Criterion 6.5CM barreled PSA upper.. same 100yds 10rds, w/ 140gr 6.5CM Amer. Gunner
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