Just orderred the Bushmaster 24" Varminter complete upper. I will drop it in the Armalite lower, mount my Leupold BDC scope & begin breakin next week. I break in as follows: Using inexpensive FMJ but a name brand - Federal,Win,PMC, Rem, (A) 5 rounds /clean - ten cycles. (B) 10 rounds / clean - 10 cycles.
Dial in scope tight. Usually smile. If any one has an alternative suggestion, lay it on me. This has been my practice for years & seems to have worked.
Dan in north Georgia