I have used several uppers but my last few have been Anderson. I have a Friend who has a mill and lapping tool but the last few uppers were really good and wouldve probably been fine out of the box. Honestly as long as the barrel fits the upper with little to no slop your probably gtg.
I would not use one bolt for two different AR-15 barrels. You can buy a Tool craft complete 6.5 Grendel BCG for less than $100 and a charging handle for $15-$20. Might as well have two complete uppers.
I just got an email sales flier from Primary Arms, Anderson charging handle $11.99. If you shop around you can get free or reasonable shipping on upper parts.
https://www.primaryarms.com/anderson-man...mmer_Build
I would not use one bolt for two different AR-15 barrels. You can buy a Tool craft complete 6.5 Grendel BCG for less than $100 and a charging handle for $15-$20. Might as well have two complete uppers.
I just got an email sales flier from Primary Arms, Anderson charging handle $11.99. If you shop around you can get free or reasonable shipping on upper parts.
https://www.primaryarms.com/anderson-man...mmer_Build