Ding Ding Ding! We have a winner! M3 Grease Gun & 1911 for the sidearm. M60 for the Coax and M2 for the Commander (with a weird PITA chain for cocking it inside of the turret).
I beg to disagree, being a graduate of US Armor School, CAV track in 1985. Yes, the M3 was used as well as the M3A1. The Coax was not a M60, but a relative of the M240 machine gun with out the stock. The Commander had a M85 inside the commander cupola on top of the turret. Both the greeze guns and the m240 ran great, but the m85 was a total POS and was always giving us problems.