Here's What You Need To Remember: Most rifles patterned after the AK-47 assault rifle are successful. The AK-47 is a reasonably simple recipe for a reliable, efficient weapon, and as long as the recipe is followed an effective weapon follows. Hungary’s AMD-65, on the other hand, is a warning of what happens when one fails to follow the winning formula.

Military rifles were for decades the primary weapon of an army. Wielded by the largest fighting branch, the infantry, rifles were used in both attack and defense. Because of their importance and the slow march of technological innovation, rifles were upgraded conservatively, with some armies, such as the German and British armies, using the same rifle for fifty years or more. Rifles simply had to work, and it was better to stick with an older one that was a sure thing than a newer rifle that was less than perfectly reliable.

Despite an inherent conservatism, there have been several examples in the last century of military small arms that have been sub-par. The relative decline of the infantry on the battlefield means that none of these weapons were bad enough to lose a war, but they were often bad enough to cause the side using them to lose engagements and lower morale.

Here are five of the worst military rifles:

Type 38 Arisaka

Twentieth century Japan’s leap into the modern world was in large part due to the wholesale import of foreign ideas and technology. One of those technologies was the famous Mauser bolt action. This was adopted into the Type 38 Arisaka rifle, and it proved a poor weapon.

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The Arisaka was a 6.5-millimeter caliber rifle. The 6.5 round had been adopted due to its lack of recoil, which was difficult for Japanese with low upper body strength to manage. In order to increase the round’s velocity and range, the rifle was fitted with a 31.4-inch barrel. The result was a rifle that was four foot ten inches long at a time when the height of the average Japanese conscript was just five foot four inches. With attached bayonet the Arisaka was often longer than Japanese soldiers were tall, making the weapon unwieldy and front-heavy.

The second order effects of using a small caliber rifle round continued. The Arisaka weighed 9.25 pounds, which was extraordinarily heavy for a soldier that might weigh just 130 pounds. Finally, the Japanese military learned the Arisaka had insufficient stopping power during the war in China, leading to the eventual fielding of the heavier 7.7-millimeter round.

M16 (Early Vietnam)

The original AR-15 rifle as conceived by Eugene Stoner was a lightweight, deadly, highly reliable weapon. Unfortunately, once issued to U.S. forces on a wide scale in Vietnam previously unseen issues cropped up that haunted the weapon for decades.

The U.S. Army, in adopting the M16, made a serious mistake: it over-hyped the weapon’s reliability while switching to an inferior gunpowder formula. Stoner and the AR-15 had used IMR 4475 gunpowder early in the weapon’s career, but in 1963 the Army substituted WC 846 ball gunpowder that burned dirtier than 4475. A direct impingement weapon like the M16 recycled gunpowder gases into the action to cycle the weapon, and experts believed the switch made the weapon six times more likely to misfeed or foul.

Meanwhile, the M16’s reputation as a reliable weapon got the better of it, and conscripts became convinced that the rifle did not actually need cleaning—when as a direct impingement weapon it actually needed more cleaning than previous firearms. The weapon also experienced premature corrosion in the bore and chamber. Although the issues were eventually cleared up the M16 was for a time one of the worst assault rifles in service.

L85

In the mid 1980s, many NATO armies looked on enviously as the British Army traded in its L1A1 rifles, based on the FN FAL battle rifle design, for the brand-new L85. Futuristic looking, the L85 was a bullpup assault rifle equipped with a 4x fixed optic and tritium night sights.

The envy, however, soon turned to pity as the L85 became known for a number of serious problems. Empty shell casings flew back into the bolt carrier, causing stoppages. The weapon’s plastic furniture was brittle and broke too often. The L85 jammed often firing fully automatic, a problem traced to the fire control group, and suffered from broken firing pins. Shockingly, the L85 actually weighed a pound more than the weapon it was originally designed to replace, the L1A1, while firing a smaller, lower power cartridge with a shorter range.

The L85 has undergone a series of revisions over the years—an effort to correct many of the weapon’s problems, bringing them up to the L85A2 standard, cost more than the price of a brand-new M4 carbine. The UK’s stores of L85s are currently being brought up to the -A3 standard, finally resulting in a firearm worthy of the UK armed forces—thirty-three years after the weapon was initially fielded.

INSAS

The Indian Army was equipped with British small arms for decades, and local factories produced of the durable and deadly Enfield No. 1 Mark III rifles and the L1A1 rifle. The Indian Small Arms System (INSAS) was an attempt to create an indigenous assault rifle for the Indian Army. Despite the plethora of good assault rifle ideas and reliable operating systems, the INSAS seemingly went in the completely opposite direction. The weapon was a complete failure.

INSAS was designed as a relatively ordinary 5.56-millimeter assault rifle. Like the M16A2 it was designed for semi-automatic and three round burst fire, but unlike the M16A2 it occasionally fires fully automatic anyway, contrary to the user’s wishes. The weapon is brittle and exceptionally prone to wear and tear, and the plastic magazines break and failed to function in cold weather. Despite the use of a fairly small 20 round magazine and low rate of fire INSAS is prone to overheating. As a final insult, the rifle is frequently reported to spray hot oil in the eyes of the shooter.

After only twenty years, a relatively short service life compared to other rifles, the Indian Army is searching for a new assault rifle to replace INSAS.

AMD-65

Most rifles patterned after the AK-47 assault rifle are successful. The AK-47 is a reasonably simple recipe for a reliable, efficient weapon, and as long as the recipe is followed an effective weapon follows. Hungary’s AMD-65, on the other hand, is a warning of what happens when one fails to follow the winning formula.

The AMD-65 was developed while Hungary was a member of the Warsaw Pact, and differs from the AK-47 in a number of ways. It shortens the sixteen inch barrel of the AK-47 barrel to just twelve inches, and as a result the AMD-65 has a shorter range and is less accurate. The weapon’s metal vented handguard heats up quickly and can burn the user’s hands. The AMD-65 also has a shorter sight radius, the distance between the front and rear sights, resulting in more frequent aiming errors. The simple wire stock makes the weapon front-heavy and, as one reviewer noted, it is impossible to get a cheek weld on for aiming down the sights.

In 2005 and 2006 the U.S. government purchased a large number of AMD-65s for arming Afghan police units. In 2010, a report in the New York Times stated the Afghan National Police were unhappy with the weapon, which in addition to the other problems mentioned they considered very unreliable.

Kyle Mizokami is a defense and national-security writer based in San Francisco who has appeared in the Diplomat, Foreign Policy, War is Boring and the Daily Beast. In 2009 he cofounded the defense and security blog Japan Security Watch. You can follow him on Twitter at @KyleMizokami. This article first appeared last year.

Image: Wikipedia.