.220 Swift Overview The  .220 Swift (5.56×56mmSR) is a semi-rimmed rifle cartridge developed by Winchester and introduced in 1935 for small game and vermin hunting. It was the first factory loaded rifle cartridge with a muzzle velocity of over 1,200 m/s (4,000 ft/s). With modern powders and precision loadings, the round is capable of pushing 1500+ meters a second.  Stats Ammunition Type Damage Bullet Velocity (m/s) Barrier Penetration Armor Piercing 40gr Ballistic Tip 4.9 1296 6.25 4 55gr Soft Point 5.4 1128 4.25 4 50gr Soft Point 5.2 1179 3.95 4 50gr Varmint 8.4 1203 1.75 4 30gr Match 4.9 1579 4.7 0 Note: Barrier penetration represents the rounds ability to go through walls and barriers. Armor piercing represents the rounds ability to penetrate body armor plates.