What gun uses 222?

222 case, was adopted along with the new M16 rifle as the . 223 Remington / 5.56mm NATO. The NATO cartridge had a capacity only 5% less than the Magnum.

How fast does a 222 bullet travel?

. 222 Remington

Bullet mass/type	Velocity	Energy
40 gr (3 g) HP	3,583 ft/s (1,092 m/s)	1,141 ft⋅lbf (1,547 J)
50 gr (3 g) SP	3,168 ft/s (966 m/s)	1,115 ft⋅lbf (1,512 J)
55 gr (4 g) SP	3,095 ft/s (943 m/s)	1,170 ft⋅lbf (1,590 J)
60 gr (4 g) VMax	2,937 ft/s (895 m/s)	1,150 ft⋅lbf (1,560 J)