6.8mm Remington SPC

6.8×43mm Remington SPC
6.8 SPC (left), 5.56×45mm NATO (right)
Place of origin	United States
Production history
Designer	Remington Arms, USSOCOM
Designed	2002–2004
Specifications
Parent case	.30 Remington
Case type	Rimless, bottlenecked
Bullet diameter	0.277 in (7.0 mm)
Land diameter	0.270 in (6.9 mm)[1]
Neck diameter	0.306 in (7.8 mm)
Shoulder diameter	0.402 in (10.2 mm)
Base diameter	0.422 in (10.7 mm)[1]
Rim diameter	0.422 in (10.7 mm)
Rim thickness	0.049 in (1.2 mm)
Case length	1.687 in (42.8 mm)[1]
Overall length	2.260 in (57.4 mm)
Case capacity	34.8–36.9 gr H2O (2.26–2.39 cm3)
Primer type	Large Rifle
Maximum pressure (C.I.P)	58,700 psi (405 MPa)
Maximum pressure (SAAMI)	55,000 psi (380 MPa)
Ballistic performance
Bullet mass/type Velocity Energy 7.45 g (115 gr) Full Metal Jacket 2,575 ft/s (785 m/s) 1,694 ft⋅lbf (2,297 J) 7.78 g (120 gr) SST 2,460 ft/s (750 m/s) 1,612 ft⋅lbf (2,186 J) 7.1 g (110 gr) Sierra Pro Hunter 2,500 ft/s (760 m/s) 1,525 ft⋅lbf (2,068 J) 5.5 g (85 gr) Barnes TSX with "tactical" factory SSA load 3,070 ft/s (940 m/s) 1,780 ft⋅lbf (2,410 J)
Test barrel length: 410 mm (16 in) [2][3][4] Source(s): [5]

The 6.8mm Remington Special Purpose Cartridge (6.8 SPC, 6.8 SPC II or 6.8×43mm) is a rimless bottlenecked intermediate rifle cartridge that was developed by Remington Arms in collaboration with members of the U.S. Army Marksmanship Unit and United States Special Operations Command^[6] to possibly replace the 5.56 NATO cartridge in short barreled rifles (SBR) and carbines. Based on the .30 Remington cartridge,^[7] it is midway between the 5.56×45mm NATO and 7.62×51mm NATO in bore diameter. It uses the same diameter bullet (usually not the same mass) as the .270 Winchester hunting cartridge.