The SMG-60 is .62 caliber. That's it's normal ammo.
Tippmann just called it an SMG-60 as a play on the name of the military's M-60 machine gun. (Or so the rumors say.)
Drilled 'Cocker body? Cover those holes with the Eye Patch
! Doc's Machine
. Fixing, fiddling and transmogrifying markers since 1998. The Whiteboard
. Vaguely paintball-related absurdity every Monday, Wednesday and Friday.