During tests, shots taken at distances ranging from 50 to 75 yards with the 6.5 Grendel at medium-sized wild hogs produced many first-round lethal hits, as well as immediate incapacitation. Two different approaches are strong contenders: the 6.8 SPC (Special Purpose Cartridge) and the 6.5 Grendel.īoth the 6.8 SPC and 6.5 Grendel have a greater potential for immediate lethality than the 5.56, based on a heavier bullet traveling at a comparable speed.

Recognizing the dilemma, military and civilian manufacturers are developing rounds for the AR platform that could bridge accurate lethality and shorter barrels. The loss of active barrel length in the M4 further cuts the overall effectiveness of particular loads of the 5.56 round that many already considered to be too small and weak. But the mobile warriors of today are frequently getting in and out of vehicles and need a shorter weapon. The poor initial performance, together with the marginal incapacitating ability of the 5.56 round, led to doubts about the Stoner design that linger today. The result was a weapon that was susceptible to jamming in the field, giving the new rifle a bad reputation right off the bat. In addition, troops were not properly trained on how to clean their new rifles. No one recognized that the ball powder substituted by the Pentagon had a greater fouling effect on the AR bolt assembly and chamber area. But the Army did not fully adopt the specific design requirements that made the original AR-15 operate effectively. The Army, looking ahead to a jungle war in Southeast Asia, picked the lightweight design to equip its new, highly-mobile soldier. Eugene Stoner and ArmaLite designed and built a lightweight, powerful, small-caliber shoulder weapon after the Army asked for help to develop a 5.56x45mm chambered military rifle in 1957.

7.62x39 vs 6.8 spc ballistics