.222 Remington

.222 Remington
Type	Rifle
Place of origin	United States
Service history
In service	1950
Production history
Manufacturer	Remington
Specifications
Case type	Rimless, bottleneck
Bullet diameter	.224 in (5.7 mm)
Neck diameter	.253 in (6.4 mm)
Shoulder diameter	.357 in (9.1 mm)
Base diameter	.376 in (9.6 mm)
Rim diameter	.378 in (9.6 mm)
Rim thickness	.045 in (1.1 mm)
Case length	1.700 in (43.2 mm)
Overall length	2.130 in (54.1 mm)
Case capacity	26.9 gr H2O (1.74 cm3)
Rifling twist	1 in 14 in (360 mm)
Primer type	Small rifle
Maximum pressure	50,000 psi (340 MPa)
Ballistic performance
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)
Test barrel length: 24" Source(s): Hodgdon [1]

The .222 Remington or 5.7×43mm (C.I.P), also known as the triple deuce, triple two, and treble two, is a centerfire rifle cartridge. Introduced in 1950, it was the first commercial rimless .22 (5.56 mm) cartridge made in the United States. As such, it was an entirely new design, without a parent case.^[2] The .222 Remington was a popular target cartridge from its introduction until the mid-1970s and still enjoys a reputation for accuracy. It remains a popular vermin or "varmint" cartridge at short and medium ranges with preferred bullet weights of 40–55 grains and muzzle velocities from 3,000 to 3,500 ft/s (915–1,067 m/s).