When the M16 rifle was introduced during the Vietnam War, it was promoted as a major advancement for U.S. forces—lighter than previous service rifles, highly accurate, and well-suited to jungle combat. But battlefield experience quickly exposed serious shortcomings. Soldiers frequently reported malfunctions, including jamming and feeding failures, sometimes at the worst possible moments in the middle of combat.
Those repeated breakdowns damaged trust in the weapon and left many troops uncertain whether the M16 would perform when they needed it most. By comparison, the AK-47 earned a reputation for remarkable reliability. Its simple construction and ability to function in mud, rain, and harsh conditions made it highly dependable in the field. For many American soldiers, that contrast only sharpened frustration with the M16’s troubled early combat record.
Adoption of the M16 rifle in Vietnam
In 1966, Gen. William Westmoreland, Commander of the US Forces in Vietnam, introduced the M16 rifle as the new standard-issue infantry rifle, replacing its predecessor, the M14. Developed by engineer Eugene Stoner in the late 1950s, it was favored for its accuracy, light weight and the amount of fire it provided.
American troops in Vietnam were given a modified version of the M16, variant XM16E1. The weapon’s adoption was largely in response to the high number of casualties resulting from the enemy’s use of AK-47s. However, controversy surrounding the efficacy of the M16 prevented it from being issued to troops stationed in Europe and the US.
The M16 rifle jammed… A lot
Early versions of the M16 were plagued by significant reliability problems. A frequent issue, called a “failure to extract,” happened when a spent cartridge became lodged in the chamber, resulting in a jam. In some situations, this caused the rifle to function more like a single-shot musket than a fully automatic weapon, leaving soldiers vulnerable during combat.
The most reliable way for soldiers to clear a jammed cartridge was to manually push it out, using a steel rod inserted through the barrel to dislodge the stuck casing.
The M16 was still seen as more effective than the M14
It was later found that the jamming problem was caused by switching to ball powder, which was meant to boost the muzzle velocity to 3,250 feet per second.
Even with these problems, the M16 was still seen as better than the M14. In fact, the US Army even called it the best rifle for combat in Vietnam. To fix the issues, they improved training, adjusted the gunpowder formula, and made sure cleaning kits were widely available—but not before a Congressional report brought attention to the problems.
A harrowing report is released
By 1967, nearly 80 percent of the 1,585 soldiers surveyed reported experiencing stoppages with the M16 rifle during combat. Many of these troops expressed their frustrations in letters to family members, detailing concerns about the weapon’s reliability. These letters were subsequently forwarded to members of Congress, prompting the House Armed Services Committee to take notice of the growing problem.
The congressional response proved effective, resulting in the creation of a Subcommittee to investigate the M16 rifle. After a thorough review, the committee’s report validated the soldiers’ complaints, concluding that the Army had failed to provide adequate training on the new weapon, neglected to ensure ammunition compatibility, and did not supply sufficient cleaning kits to prevent malfunctions.
Despite these findings, the military continued issuing the M16 to troops. As reliability issues persisted, confidence in the rifle eroded among service members, many of whom began seeking alternative solutions in the field.
Picking up the AK-47
During the Vietnam War, many American troops developed a grudging respect for the AK-47, the standard weapon carried by Viet Cong and North Vietnamese forces. In the 1950s, China began manufacturing its own variant, the Type 56. Slightly lighter and more compact than the original Soviet design, it retained the ability to fire in both semi-automatic and fully automatic modes.
The AK-47 became known above all for its durability and reliability in combat. It could withstand mud, moisture, and rough handling while continuing to operate with minimal maintenance. Its simple, rugged design also made it easy to learn and use effectively, even for fighters with limited training. In the extreme heat, dense terrain, and constant humidity of Southeast Asia’s jungles, that dependability made it an especially effective battlefield weapon.
Many American soldiers became increasingly frustrated with the M16 rifle, particularly because of its tendency to jam under combat conditions. By comparison, the AK-47 earned a strong reputation for reliability, leading some U.S. troops to prefer it in the field. Soldiers came into possession of AK-47s in different ways—some were taken from enemy fighters, while others changed hands through informal trades or discreet purchases.
Even as reports of malfunctions spread throughout the ranks, military leadership continued to argue that the M16’s problems stemmed primarily from improper handling or inadequate maintenance rather than defects in the rifle’s design. For many troops on the ground, however, that explanation did little to ease concerns, especially when reliability could mean the difference between life and death in combat.