I hadn't stopped to count then in a while, let's see:
Handgun: .25ACP, .32ACP, .32 S&W, .32-20, 9mm Luger, 9mm Largo, .380 ACP, .38 Special, .357 Magnum, .38-40, .44 Special, .44 Magnum, .45 ACP, .45 Auto Rim, .45 Colt.
Rifle: .223, 6.5 Swedish, 6.5 Carcano, 7mm Mauser, 8mm Mauser, .30 Carbine, .308 Winchester, 7.62x39 Russian, 7.62x54 Russian, 7.7mm Japanese, .30-30 Winchester, .30-06, .303 British, .577-450 Martini-Henry.
Shotgun: .410 ga., 20 gauge, 12 gauge.
So, 32 calibres or gauges, altogether. Calibres I shoot would also include .22 LR, .22 Magnum, .44 blackpowder revolver, and .50 blackpowder rifle.