Geissele HICAR rifle: how it handles high-pressure M855A1+ 5.56

Key points: Geissele HICAR rifle handles

• HICAR asks for an 11- to 12-inch 5.56 carbine that holds up to M855A1+ at roughly 82,000 psi; at the September 15 and 16 pitch day each approved bidder fired about 600 demonstration rounds and gave a 30-minute presentation, and Geissele is the only company to show its entry publicly.
• In the host's experience high-pressure ammo shoots with little or no added felt recoil, because what matters is when peak pressure occurs and how gas is vented; with sensible propellant and port placement the rifle still runs standard ammo, and the program requires Mk 262 and M855 performance to stay unchanged.
• The barrel uses a proprietary steel developed with Carpenter Technology and the US Army; the published composition points to high surface hardness balanced against toughness, with manganese for strength and vanadium for abrasion resistance, though Geissele admits high-pressure testing on it is still limited.
• The gain-twist barrel ends at 1:7 with a claimed 1 MOA; the host expects the steel to carry most of the wear resistance, with the gain twist adding at most a marginal gain.
• A three-port gas system spreads gas load for softer recoil and longer barrel life, but the host argues the bolt lugs take the real abuse, and that the military is moving toward standardized bolt-thrust requirements for high-pressure guns.
• Geissele's answer is a reinforced proprietary bolt, separate from its stress-proof bolt; alloy-cased ammo reportedly produces bolt thrust close to standard brass, unlike NAS3 cases, and the program sets an 8,000-round threshold against a 20,000-round objective.
• The rifle is ambidextrous, about 6.6 lb, and shares the Super Duty's trigger and ACH charging handle; Geissele does not plan to sell it unless true high-pressure ammo reaches the commercial market, and the company is still on its first barrel establishing a wear limit.

About this Ballistics Focu video

Geissele HICAR rifle breakdown from Boondock Ballistician: what is public about Geissele's entry in SOCOM's HICAR program, an 11- to 12-inch carbine built to survive high-pressure M855A1+ 5.56 at about 82,000 psi. Working without the rifle in hand, the host covers the barrel steel, gain twist, three-port gas system and reinforced bolt, and explains why high-pressure ammo can feel softer and why bolt lugs wear before barrels. Recorded before reports that Geissele may be out of the bid.

Transcript: Geissele HICAR rifle