6.8 mm Remington SPC
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6.8 mm Remington SPC (or 6.8 x 43 mm) is a new rifle cartridge that was developed for US SOCOM. It is touted as being superior to both 5.56 mm NATO and 7.62 x 39 mm, as well as being easily adaptable to current 5.56 mm NATO firearms with minimal modifications. The U.S. Army Marksmanship Unit also collaborated in the development of the new cartridge and the Barrett Firearms Company produced the modified upper receiver for the M16, known as the M468. Although the main objective was increased lethality, the new cartridge also displays superior accuracy and ballistic characteristics.
It has ballistics similar to the British .280, which is more than 50 years old, but due to improved powders the 6.8 mm has a smaller case. The 6.8 mm SPC (Special Purpose Cartridge) has a muzzle velocity in the 2600 feet per second (790 meters per second) range from a 16 inch ( 406 mm ) barrel using the standard 115-grain bullet. It uses bullets of the same diameter as the popular American hunting cartridge .270 Winchester, lending the possibility of civilian sporting use.
Performance
Initially assigned only to US Special Operations unit, the new cartridge was widely praised for its increased accuracy at longer ranged, greater terminal ballistics and the ability to penetrate obstacles such as concrete block walls when compared to the 5.56 mm NATO cartridge.When compared to the more powerful and well-established 7.62 mm NATO cartridge, the 6.8 mm falls shorter in all these areas but has less recoil, is more controllable and is more likely to fragment in tissue at close to medium range, creating greater damage to the target. While the 6.8 mm generates around 2000 ft·lbf of muzzle energy with its 115 grain bullet, the 7.62 mm NATO (M80) launches a 147 grain bullet at 2750 ft/s for 2460 ft·lbf of punch.
The principal advantage of the 6.8 mm is that it permits firearms designed for the short 5.56 mm to fire a more powerful cartridge.
The round has also been favorably review by hunters, who consider it an excellent medium sized hunting cartridge. Its power, however, is only equivalent to the .243 Winchester, which is generally regarded as a marginal deer cartridge. (The .243 cranks out 1950 to 2050 ft·lbf of muzzle energy, depending on the load selected.)
Primary criticism about the 6.8 round has centered around its poor long-range (greater than 400 yards) performance compared to the NATO standard 7.62 or the competing 6.5 mm "Grendel" round. While the round is generally intended for use at shorter ranges, this handicap has somewhat dampened the inital enthusiasm over the SPC round, and given competitors like the Grendel or improved 5.56 mm rounds an opportunity to compete for acceptance.
Muzzle velocity from a 20 inch ( 508 mm ) barrel
- 7.45 g (115 gr) Full Metal Jacket(FMJ): 853 m/s(2,800 ft/s),
- 7.45 g (115 gr) Boat Tail Hollow Point (BTHP): 853 m/s (2,800 ft/s)
- 7.45 g (115 gr) Sierra Match King (SMK): 853 m/s (2,800 ft/s)
See also
- List of firearms
- List of handgun cartridges
- List of rifle cartridges
- List of individual weapons of the U.S. Armed Forces
- 6.5 Grendel
External links
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