Help with caliber(s) 30 cal


Apr 1, 2003
Fairbanks, Alaska
I just got a Armalite AR10A4 (20"brl) and am interested in upgrading the upper. I spoke with a company who told me that they can make an upper in any caliber that is spawned off of the .308. Any help in what calibes this would be would be appericated.


I have chambered AR-10s in 300 WSM, 6.5 WSM, 6.5 SAM, .308 WIN., 308 win. IMP., .243 IMP., 22-250 IMP., 6 mm. IMP.,
and 6 BR.

Basically, anything that will function less than 2.830" OAL. and will use a boltface between .480" and .540" will probably be workable.


My reamer has a 40 degree shoulder, and about .012" taper with a .334" neck.

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