American Big Rigs

12-GAUGE ACTION TYPE ENGINEERING: 4 DESIGNS.
Pump-action and gas-operated. Public data on ARGO gas system, dual extractors, and AK-style action. For mechanical design education only.

US PLATFORM ENGINEERING: 1936-PRESENT.
Gas-operated and direct impingement. .30-06 to 7.62 NATO. Public data on cold hammer forged barrels and MIL-STD-1913 rails. For museum and mechanical history education only.

PRECISION CHASSIS ENGINEERING: 3 PLATFORM DESIGNS.

USA, Russia, China. Bolt-action and gas-operated. Public data on modular multi-caliber systems and match-grade barrels. For mechanical design education only.