ICAR, HICAR and the M7: SOCOM's carbine programs after the M4

Key points: ICAR HICAR M7 SOCOM's

• The M4 arrived as a shorter, lighter M16 for close-quarters work and has absorbed heavier barrels, launcher mounts and fire-control changes ever since — and the host's closing call is that the military wants compact and lightweight, so expect roughly 50 more years of M4s and 5.56.
• NGSW is not the first run at replacing the M4: the Individual Carbine program died quickly because it chased reliability and ergonomics, and only marginal gains could not justify the cost. NGSW instead chased performance — lethality, range and barrier penetration for peer conflict.
• On the M7's round he is unreserved: 6.8 hovers around 3,000 feet per second with roughly 2,500 to 3,000 foot-pounds of muzzle energy, and lethality testing backs it, so the range and penetration goals were met. Soldier perception started positive on feel alone, then turned once testing ran past a few rounds and the weight, ammunition capacity and dual-logistics problems landed.
• SOCOM answered with its own initiative, the Sons of Liberty Gun Works Mark 1, deliberately staying on 5.56 so it can run legacy M4A1 lowers, existing magazines, existing training and the existing supply chain while staying shorter and lighter than the M7 for the distances SOF actually fights at.
• ICAR adds 6mm ARC to push the effective envelope from about 300 meters to 600 without the bulk of 6.5, .270 or .308. He shrugs at why not 6.5 Grendel or a Max-type round: ARC is faster with more energy than Grendel, and it simply had the head start in prototypes, testing and high-pressure work. He finds the SureFire ICAR a touch tiring to carry, but a real ballistic step up.
• HICAR takes the other road — a more robust M4 built to eat M855A1+ high-pressure ammunition in an alloy case while keeping M4 lower compatibility and legacy 5.56 accuracy, so units can absorb the extra wear only when the mission calls for it. It is still in development, which is why the fielded Mark 1 keeps its place.
• High-pressure 5.56 does not cancel ICAR, because high-pressure 6mm ARC scales up alongside it; ICAR's real aim is putting 14.5-inch 5.56 performance into an 11.5-inch package rather than chasing raw energy. The MRGG-A award of a small-frame 6.5 Creedmoor to LMT sits above it, still heavier and bulkier — and, he notes, SOCOM programs have a habit of surfacing for a few years and vanishing.

About this Ballistics Focu video

ICAR, HICAR and the M7 explained: Boondock Ballistician, who says he worked on early NGSW weapon and ammunition prototyping, walks the carbine programs lining up behind the M4 and the ballistics driving each one. The M7 in 6.8 hits roughly 3,000 fps and 2,500 to 3,000 foot-pounds of muzzle energy but carries weight, capacity and logistics costs; SOCOM's Sons of Liberty Gun Works Mark 1 keeps 5.56 and M4A1 lowers; ICAR moves 6mm ARC into a compact platform to stretch engagements from 300 to 600 meters; and HICAR builds a tougher M4 around high-pressure M855A1+ ammunition in an alloy case.

Transcript: ICAR HICAR M7