Mysteries of the 'A' Suffix

[jmoore]

And there's another reason some barrels shoot better than others- Straightening before the final turning results in unbalanced internal stresses that are "built in". The lucky few barrels where everything went correctly were then most likely indifferently bedded...

Ever so reasonable to select rifles for sniper conversion by actually testing them! Not everybody (nations) went to so much trouble.

BTW, straightening finished barrels SOMETIMES works OK, other times, as in Son's example, they refuse to cooperate. I once straightened a 16" AR barrel that was used to pry open a door (about 5-10 degrees of bend!) that is still stupidly accurate after 20 years hard use. (Not exactly mine anymore, had to let the womenfolk have it.)