get lessons if you need them - Uncle Sam gave me those in the Marine Corps
He taught you how to shoot a gov't issued M16A1 (or maybe it was an M16A2 - forget when they changed over).
And that was a while back.
You need a refresher. Practice with what you have.
By the way, Semper Fi
(USMC '74-'78 MCRD San Diego, MCCES 29 Palms, 2nd Mar Div Camp Lejeune, MOS 2841 Radio Repair Tech)