M16 in Vietnam: why Stoner's rifle jammed and how the Army fixed it

Key points: M16 Vietnam Stoner's rifle

• Vietnam's jungle fighting did not suit the M14, a long, heavy 7.62 NATO rifle that was hard to control on automatic and heavy to carry ammunition for.
• Eugene Stoner, a former Marine aviation ordnance technician, brought aircraft-industry aluminum and synthetics to ArmaLite's AR-10 and then the smaller, high-velocity AR-15.
• Under the Pentagon's Project Agile, roughly a thousand AR-15s went to South Vietnam for testing, and the combat reports came back strongly positive.
• As the war escalated, the Air Force adopted the M16 and the Army the XM16E1, which the 173rd Airborne and 1st Cavalry Division carried into early fights such as Ia Drang in 1965.
• Failures to extract came from stacked decisions: ball powder that fouled and raised the cyclic rate, unchromed chambers, heat and humidity, and inadequate cleaning kits and training.
• By 1967 soldiers' letters home reached Congress, and the hearings traced the problems to procurement and fielding changes rather than to the rifle's basic design.
• A chrome-plated chamber and later bore, proper cleaning kits and better training produced the M16A1, the start of a line running through the M16A4 and M4.

About this Gun Review video

M16 history from Lujan: how Eugene Stoner's aluminum-and-plastic AR-15 went from Project Agile trials in South Vietnam to the XM16E1 carried at Ia Drang, then began failing to extract once ball powder, unchromed chambers, humidity and missing cleaning kits combined. Letters home brought congressional hearings, and chrome lining, cleaning kits and training produced the M16A1. The rifle on camera is a semi-automatic H&R M16 clone.

Transcript: M16 Vietnam Stoner's