After the conclusion of the Second World War, drawbacks to the iconic M1 Garand design became apparent. Though the rifle benefitted from the powerful .30-06 cartridge, it was hindered by its low 8-round capacity and could fire in semi-automatic only. Though the rifle also served on the Korean Peninsula, its shortcomings were affirmed.
What the United States needed was a new, fully-automatic rifle.
A New Solution
The idea of an automatic rifle paired with an intermediate cartridge was first pioneered on a large scale by Nazi Germany during the waning days of the Second World War. Many of Germany’s dying gasps were technological flops, though their Sturmgewehr 44 (German for “Assault Rifle 44”) represented nothing less than a revolution in firearms design. The rifle was chambered in the intermediate 7.92×33mm Kurz cartridge and combined the high rate of fire of a submachine gun with the stopping power of a rifle and the compactness of a carbine.
Though an attempt was made via the M14 to put a full-powered, fully-automatic rifle into the hand of soldiers and Marines, the design was inadequate. Rather than an intermediate-power cartridge, the M14 was chambered in the now NATO-standard 7.62x51mm cartridge, which was much too powerful for fully-automatic firing — necessitating yet another redesign after just five years of service.
Enter the M16
The M16 was based on the AR-15 rifle, now a ubiquitous American rifle chambered in the intermediate .223 Remington cartridge. Like the StG 44, the M16 brought a high rate of fire and lightweight profile onto a magazine-fed platform. The M16 rifle weighed less than the heavy, wooden-stock M14 and was much more controllable during automatic fire. Its advantages were immediately obvious.
Despite the M16 superior characteristics, there were however several drawbacks that became apparent — and deadly — after its Vietnam combat debut.
Jams and other malfunctions were a common complaint that contributed to solder’s perception of the M16 as an unreliable rifle. Another complaint was the M16’s lack of stopping power compared to the M14’s larger 7.62x51mm cartridge, especially when shooting through the dense jungle foliage endemic to Vietnam, which caused bullets to lose velocity and stopping power.
Eventually, reliability issues were addressed by improved soldier instruction on how to clean and maintain their M16 rifles, and by a better distribution of cleaning kits. After these and other design improvements were incorporated into the M16 design, confidence in the rifle increased.
Since its introduction, the M16 has spawned a number of copies, variants, and derivative rifles in both the United States and abroad, though has largely been supplanted by the very similar, though more compact M4, essentially a carbine version of the M16. Another rifle visually similar, though mechanically different than the M16 has recently been adopted by the United States Marine Corps, the M27 rifle — and coincidentally the rifle that was used to shoot Osama bin Laden.
Still, the M16 rifle filled an important capability gap when introduced into service in the 1960s in Vietnam.
Caleb Larson is a Defense Writer based in Europe. He holds a Master of Public Policy and covers U.S. and Russian security, European defense issues, and German politics and culture.