Key point: Outdated ergonomics and a poor design make for a bad gun.

The M14 is the U.S. military’s worst service rifle. It served as the standard-issue rifle for just six years—by the most generous estimates, half that of the U.S. Army’s second shortest serving rifle, the Krag-Jørgensen. The design itself is fraught with problems.

The process of creating it was even worse and led to the dissolution of the U.S. Ordnance Corps and Springfield Armory, the largest producer of American military small arms in history. The modern company, also called Springfield Armory, has no relation to the former government armory and simply leverages the name for sales.

So why is the M14 itself terrible? After all, many soldiers are have said to prefer the M14 to the M16 during the Vietnam War, and the rifle has been described by other authors as a “phoenix” rising again and again when the U.S. military needed a rifle that could fire the larger 7.62mm NATO round.

Quite simply, the M14 has outdated ergonomics, is poorly designed, and is inaccurate. The rifle can be accurized but will not stay that way unless constant care and maintenance are performed on it.

Ergonomics wise, the M14 had a traditional rifle stock due to the traditional sensibilities of the U.S. Ordnance Corps. Most contemporary rifles, including the Soviet AK and Belgian FAL, have a pistol grip to aid in controlling fully automatic fire. The M14’s traditional rifle stock makes it climb far more than its competitors while in rapid and fully automatic fire and also makes follow up shots slower.

The traditional stock design would become a perennial issue with the M14. While later rifles with free floating barrels like the G3 are a snap to accurize, the M14’s stock design requires proper bedding of the action in the stock for good accuracy.

This accuracy point may be the most controversial because an M14 variant, the M21, served as the U.S. Army’s “sniper rifles” for almost seventeen years. But the M21 was only kept accurate by an incredible range of modifications that brought the rifle into a precise balance—that could be easily disrupted.

One expert with hands-on experience with the M21, the late Kevin “Hognose” O’Brien, a former U.S. Army Special Forces Weapons Sergeant, describes it as “a fiddly, unstable platform” that they were not even allowed to field strip for fear of disrupting the internal tuning of the weapon that allowed it to be accurate.

The same story was unfortunately repeated many years later when M14s were brought out of retirement and placed in new metal Sage chassis to be the U.S. Army’s “new” marksman rifle, the M14 EBR-RI. These rifles proved to just be as finicky as the older M14s and M21s.

Ash Hess, a former U.S. Army NCO with four combat tours and extensive experience as a marksmanship instructor, describes stripping down the M14 EBR to clean them prior to a deployment and tripling the inaccuracy of the guns, from 1 MOA to 3 MOA, as the chassis had to be precisely torqued together for the guns to be accurate.

So, what is the M14 good at? Some say that the 7.62 NATO round has superior penetration against materials.

This is true only in limited cases. The Hitch report shows largely similar results between the AR and M14 on most material penetration tests, with the exception of penetration on pine boards at 500 yards, where the M14 outperformed the AR. In contemporary tests, similar results were found, with the M14 only significantly outperforming the M16 on wood (as well as during separate 55-gallon barrel tests). However, the authors of both tests concluded that the improved performance on wood likely would be largely irrelevant in real-world conditions.

Some say the M14 is more durable, reliable, and lasts longer than the plastic and aluminum M16.

The 1962 Hitch report directly contradicts this. The M16 (referred to as the AR-15 at the time as it was not adopted yet), is said to have double the barrel life of the M14. The M16 is also said to be better suited for the stresses of jumping out of an aircraft with, as the M14’s flash hider and barrel are said to bend while jumping from an aircraft.

Reliability wise, the AR-15 has fewer moving parts and was found to be more reliable with proper ammunition than the M14. Ash Hess said that his EBRs were particularly unreliable as the combination of Iraqi sand, the standard CLP lubricant, and the M14’s open action lead to the action getting sticky.

Bad experiences with the M14 aren’t exclusive to Americans. The U.S. Army gave 40,000 M14s to the Estonian Defense Forces following their regaining of independence in the 1990s. The Estonians have fielded their own “accurized” version of the M14, the M-14TP2. From soldier accounts, this rifle is not popular at all and is known as “täitsa pask” or “fully terrible.”

Charlie Gao studied political and computer science at Grinnell College and is a frequent commentator on defense and national security issues. This article first appeared earlier this year.