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The M-14 and the AR-15 are two of America’s general-issue, military rifles. The AR-15 is, without question, the dominant player in the field in recent years. Despite being an older design, the M-14 still enjoys a small, but loyal following. If you are considering purchasing a rifle, which should you consider? This article will explore the differences between these two rifles, which are significant. We will explore the pros and cons and try to help you make an informed decision.


What is an M14?

The M14, officially the United States rifle, is one of the shortest-lived rifles in American military service. Adopted in the late 1950s and issued through 1964, this automatic weapon lasted only five years in general-issue service. The M14 was a true battle rifle and was chambered in a full-power rifle cartridge, and it was the last semi-automatic rifle issued by the U.S. military that was made of steel and walnut.

The M14 was a direct successor to the M1 Garand which was preceded in military service by a bolt-action rifle. The similarities between the Garand and M14 are readily ap

parent. Both share similar lines, have the safety inside the trigger guard, and share the same rotating bolt mechanism. The differences between the

two rifles are obvious, too. The M14 has a flash hider, a 2” shorter AR-15-barrel length and fires a shorter cartridge from a 20-round, detachable box magazine. With some aesthetic changes, the M14 looks fairly modern compared to the Garand.

However, the M14 design is complex and can be very difficult to perform even routine maintenance if not trained properly.

Despite its short run as a main battle rifle, the M-14 has endured as a military rifle for special purposes. As late as the conflicts in Iraq and Afghanistan the M14 was being deployed as a designated marksman’s and anti-materiel rifle. In fact, the author was issued a M14 based DMR during an Afghanistan tour in 2007. The M14 is still in limited use by some law enforcement agencies and has also retained a portion of the civilian market, as well.


What is an AR-15?

First and foremost, the prefix AR in AR-15 does not stand for “Assault Rifle.” The AR refers to the company Armalite owned by the designer Eugene Stoner, with the designation AR-15 meaning Armalite Rifle, Model 15. The original design was created as a survival rifle for downed pilots. The AR-15 was eventually modified to full-auto fire and adopted by the

U.S. military as its general-issue rifle. M16 and its variants like the M4 have already lasted almost six decades in military service. Arguably it could last much longer in the hands of American troops. Even the M5 that has been announced as a replacement is clearly based in the M16/M4/AR-15 design.


The AR-15 is a semi-automatic, gas-operated, magazine-fed rifle. It is the basis of many other modern platforms including the AR-10 rifle in 7.62×51. Though most commonly chambered in 5.56 NATO, the AR-15 is available in a number of other calibers including the very popular .300 Blackout. The AR-15 style rifle is extremely well supported by the afterma

rket, easy to shoot, accurate, and light recoiling.


It will undoubtedly be popular with civilians for a long time to come. The Armalite Rifle was a radical design when introduced. It had a lot of “space age” features for the time, including being based on aluminum upper- and lower receivers and having plastic furniture. Though it had some teething problems early on, the AR-15 has truly become “America’s rifle,” as it has been the number one selling sporting rifle for many years.


The M-14 and AR-15: Similarities and Differences

The differences are far more numerous than the similarities between these two. Though both are military-style weapons, both reflect vastly different levels of technology. The M14 is still sold predominantly with a wooden stock. As troops learned in Vietnam, heat and moisture can warp the wood, causing severe accuracy issues in an already moderately accurate rifle. The  AR 15, which is made of aluminum, polymer, plastic, and other more modern materials is far less affected by this phenomenon.


The AR-15 is also extremely adaptable. A single AR lower can be topped with receivers in various calibers and configurations. The M14…well, is what it is. You can drop it into a new stock, but it’s still a long, heavy rifle chambered in 7.62. The ease of mounting accessories through the use of picatinny, M-Lok, and other mounting adaptations have made the AR style of rifle very modular and adaptable.


The size and weight difference between these two is enormous. The U.S. Arms M4 UTAW Pro in 5.56, an excellent exemplar of a modern AR-15 rifle, weighs in at 6.85 lbs. and has an overall length of 35 to 39 inches. Compare that to the M14s 9.5-pound weight and 44-inch overall length. The M14 is a massive rifle, unsuited to most conditions other than open terrain.


What caliber is an AR-15 and M-14?

The M-14 and the AR-15 reflect fundamentally different philosophies. The M-14 is the product of “big bore heavy” bullets fired by larger caliber rifles. Chambered in 7.62x51mm NATO (.308 Win), the M-14 is a rifleman’s rifle. The choice of a high-power rifle cartridge rather than an intermediate cartridge is the main cause of the M14’s demise in military service, however.


There are several disadvantages of the larger rifle round. First it is physically larger. This means that an equivalent amount of ammo is heavier and takes up more space. This reduces magazine capacity and makes a standard loadout of ammunition a greater burden. The guns that fire a larger cartridge also must be physically larger. But that’s not all.


Heavier ammunition also generates more recoil. This means the rifles that fire heavier bullets must be heavier. The additive effect of recoil is on full display when the rifle is fired in fully automatic mode. This is not a huge concern for civilian users, but without question contributed to the M14’s discontinuation in regular military service.


The AR-15’s flagship chambering, 5.56×45 NATO reflects a school of thought that prefers very light, very high-velocity bullets. Though the AR-15 is chambered in a number of calibers these days, the most popular by a mile is the 5.56x45mm NATO. There are all sorts of advantages to the 5.56, not the least of which is its widespread appeal. This helps to keep ammunition very affordable and widely available.


The AR-15’s ammunition is smaller and lighter than the M14s. In fact, 5.56 rounds will weigh about half what an equal number of 7.62 cartridges weigh. The AR-15 feeds from a box magazine with a standard capacity of 30 rounds. This magazine is still lighter than the M14’s 20 round magazine and requires fewer magazine changes. The AR-15’s ammunition also produces less recoil, making follow-up shots and long-range sessions much less taxing, though with a U.S. Arms Company M-905 Talon Muzzle Brake the recoil of both calibers is reduced to almost nothing.


Which semi-automatic rifle should I buy?

So, which of these two should you buy? Without hesitation we say the AR-15. The M14 is certainly a neat rifle, and an important piece of history. It has been fielded in every conflict since Vietnam, in some form or fashion. It has handsome good looks. It fires a high-power cartridge. The M14 is a far more complex platform when considering maintenance and/or modification.


Modern AR-15s like the U.S. Arms UTAW Pro are the apex of semiautomatic rifle performance. The AR-pattern rifle has been perfected over the past sixty years. Over two decades of combat has proven the AR-15 and its military brethren – the M16 and M4 – incredibly reliable platforms, even in the most inhospitable places. Constant improvement by the conventional military, special operations forces, and firearms industry has elevated the AR-15 to one of the most prolific, reliable, and accurate general-issue rifles in history.


The UTAW series of rifles from U.S. Arms epitomize this evolution from the early AR-15. Our 7075-T6 receivers are mated to each other and feature the Cam-Lock for the tightest lockup possible between upper and lower receivers. The charging handle is the Radian Raptor and is fully ambidextrous. The cold hammer forged 4150 chrome moly barrel offers extreme accuracy and durability. All USAC rifles are available with a Cerakote finish which is impervious to weather and will last a literal lifetime. All these features would have been coveted in a Vietnam-era M16, and all are available across our entire line of AR-15 style rifles.


As we said earlier, the M14 is a neat piece of history and we’re not bashing it. But it’s place as serious-use rifle is severely limited. We highly recommend choosing an AR-15 for any defensive or law enforcement purpose. And of course, we recommend the very best AR-15s: those from U.S. Arms Co.