I Was A Fan Of The M249 Light Machine Gun SAW – The M249 light machine gun has been in active service in the US military since the mid-1980s. Since the Army retired the Browning Automatic Rifle (BAR) in the early 1960s, the squad needed more firepower than a designated automatic rifleman could provide. 

The Army tried to designate one squad member as an automatic rifleman using an M16A1. This attempt was not viable for producing a “base of fire” with that weapon. The military then used the M60 machine gun, affectionately known as “The Pig.” However, a new weapon was needed in the late 1970s and early 1980s. 

South China Sea (June 5, 2006) Midshipman 2nd Class John D. Jones gets small arms training on the bridgewing of the amphibious dock landing ship USS Harpers Ferry (LSD 49). Harpers Ferry is underway completing her Spring Patrol. U.S. Navy photo by Journalist 2nd Class Brian P. Biller (RELEASED)

The Squad Automatic Weapon (SAW) was developed based on the FN Herstal Minimi light machine gun, which was adopted by the US military in 1986 and is now in use by more than 30 countries. 

The M249 Squad Automatic Weapon, adopted by the U.S. military in the 1980s as a licensed variant of the Belgian FN Minimi, has served as the primary squad-level light machine gun for over four decades. 

The M249 SAW Was A Lighter, More Versatile Weapon Than The M60

Having carried one myself, I found the SAW much lighter than the M60; the ammo also weighed less, meaning the gunner (me) could carry more, and it was easier to carry in dense environments, where the “PIG” would get hung up.

Chambered in 5.56x45mm NATO, it was designed to give infantry squads sustained automatic fire without the weight and logistical burden of a heavier machine gun. Like any piece of equipment that has stayed in service this long, it has clear strengths and well-documented drawbacks

Capt. Kirk Freeman with the 98th Training Division and a member of the U.S. Army Reserve Marksmanship Team, qualifies with his M4 rifle during the first day of the U.S. Army Forces Command Weapons Marksmanship Competition Sept. 21, 2015, at Fort Bragg, N.C. The three-day FORSCOM competition features 27 marksmen from the U.S. Army, U.S. Army Reserve, and the National Guard in events for the M9 pistol, the M4A1 rifle, and the M249 SAW, or Squad Automatic Weapon, to recognize Soldiers who are beyond expert marksmen. The multi-tiered events challenge the competitors’ ability to accurately and quickly engage targets in a variety of conditions and environments. (U.S. Army photo by Timothy L. Hale/Released)

Lance Cpl. Daniel Vitellaro with 1st Combat Engineer Battalion, fires an M249 light machine gun during a two-week machine gunners course at Marine Corps Base Camp Pendleton, Calif., Jan. 15. The course taught Marines how to effectively operate machine guns in combat scenarios.
(U.S. Marine Corps photo by Lance Cpl. Joshua Murray/Released)

The M249 SAW is an individually carried, gas-operated, magazine- or disintegrating metallic link-belt-fed, light machine gun with fixed headspace and quick-change barrel feature. The M249 can engage point targets out to 800 meters, firing the improved NATO standard 5.56mm cartridge. 

Pros Of The M249

The SAW is the primary source of firepower for the standard fire team. The gunner can use 30-round M16 magazines in an emergency or if the gunner runs out of ammunition, or linked ammunition from pre-loaded 200-round plastic magazines. 

Sustained automatic fire. The M249’s core purpose is suppression, and it excels at it. Belt-fed and air-cooled, it can deliver a much higher volume of sustained fire than a standard rifle, giving a squad the ability to pin down an enemy position while other elements maneuver.

Ammunition commonality. Because it fires the same 5.56mm round as the M4 and M16 family, logistics are simplified compared to older squad weapons that used different calibers. In a pinch, the SAW can also accept standard M16/M4 magazines, giving it flexibility if belted ammunition runs out.

U.S. Marine Corps Lance Cpl. Noah Larose, motor transportation operator, Combat Logistics Battalion 6, 2nd Marine Logistics Group, fires an M16A4 rifle during a rifle marksmanship qualification on Alpha Range at Stone Bay on Camp Lejeune, North Carolina, Oct. 3, 2019. Marksmanship qualification is required once a year for all Marines and consists of two tables that test the individual’s knowledge and skills while operating the M16A4 rifle or the M4 carbine in order to maintain mission readiness. (U.S. Marine Corps photo by Lance Cpl. Ginnie Lee)

Range and effective fire. With a quick-change barrel and open-bolt operation, the M249 can maintain a higher rate of accurate fire over longer engagements than a rifle without overheating as quickly, and its effective range exceeds that of a standard service rifle.

Battlefield-proven reliability (under normal conditions). Decades of use across multiple conflicts have ironed out many early reliability issues, and armorers and troops are broadly familiar with its maintenance requirements. 

Squad-level firepower without a crew. Unlike the M60, which required a two-man crew, the M249 could be operated effectively by a single gunner, keeping the squad’s footprint small while still providing a genuine base of fire. 

M249 LMG Specs

Caliber: 5.56×45 mm NATO.

Weight (with bipod and tools): 16.98 lbs

200 Round Box filled: 6.92 lbs

100 Round Magazine: 3.00 lbs

Spare Heat Shield, Spare Barrel

Assembly and Barrel Bag: 7.00 lbs

Length (Complete Gun): 39.96 in

Barrel Assembly (Spare): 20.50 in

Rifling Twist (RH): 1 turn in 7 inches

Rate of Fire: 700-1,000 rpm

Max. Effective Range: 800- 1,000 m (875-1,094 yd).

Stock Fixed

Problems (Cons) With the M249

Many soldiers who have carried the M249 into combat report issues with it. Some of those include design flaws, such as many gaps that collect dirt, making the weapon unreliable in dirty environments. 

Other issues include problems feeding rounds smoothly with standard rifle magazines and a tendency to jam during sustained fire. Some troops have also criticized the difficulty of maintaining proper lubrication in harsh conditions. 

The use of magazines is discouraged, however, due to a high incidence of malfunctions. The gunner’s basic load is 600 rounds of linked ammunition. Personally, I had very few issues with using magazines or with the well-documented feeding problems and jams associated with them. 

It should be noted, however, that in training using blank ammunition, those issues were much more prevalent. Using live ammunition, it was much less so.

The issue with the box magazine was that it was very noisy when carrying the weapon. In moving through thick brush or jungle environments, it was loud, like carrying a bag of ball bearings in a plastic box.

The military was concerned that the 5.56mm round fired from the M249 isn’t strong enough to penetrate the improvements in body armor, especially the Chinese and Russian types, our potential adversaries in the near future. 

Weight. A loaded M249 with ammunition can weigh well over 20 pounds, a significant burden for the gunner on top of body armor, water, and other combat load. While better than the M60, it remains a persistent complaint among infantry units.

Reliability issues in adverse conditions. The weapon has a reputation for being finicky in sandy, dusty, or muddy environments, conditions frequently encountered in places like Iraq and Afghanistan. 

Reports from those conflicts cited jamming problems that some units addressed through aftermarket modifications or by requesting entirely different systems.

Bulk and maneuverability. Its size makes it harder to handle in close quarters, vehicles, and tight urban environments than a standard rifle, limiting its usefulness in certain mission sets, such as room clearing.

Barrel and ammunition management burden. While the quick-change barrel helps, sustained firing still requires careful barrel management to avoid overheating, and the gunner typically has to carry a second assistant gunner’s worth of ammunition, adding logistical strain to the squad.

Aging design. As a design rooted in the late 1970s and early 1980s, the M249 lagged behind more modern automatic rifles in areas such as ergonomics, accessory rail integration, and overall weight efficiency, prompting the U.S. Army to begin fielding replacements, such as the XM250, under the Next Generation Squad Weapon program.

The Replacement of the M249 

The Marine Corps replaced the M249 SAW at the infantry squad level with the M27 Infantry Automatic Rifle, choosing a more accurate, magazine-fed weapon to shift doctrine toward precision fire.

With those issues listed above needing to be addressed, the Army set about finding replacements for the M4 Carbine, the M16A4 rifle, and the M249 machine gun. SIG Sauer won the Next Generation Squad Weapons competition; after testing was completed, the Army began fielding the M7 rifle and M250 machine gun. 

Both weapons will chamber the 6.8mm/. The .277-caliber round offers better accuracy, range, and penetration, and can defeat advanced body armor. However, these new weapons will only be issued to front-line combat and special operations units. 

Army support and non-combat units will continue to use the M4/M16A4 and the M249 until the M250 becomes available to them. However, it is only a matter of time before those weapons are fully retired, as using legacy weapons creates logistical issues, especially in combat. 

The M249 SAW Was A Good Weapon For Its Time: I Know, I Carried It 

The M249 SAW was a workhorse of squad-level firepower, valued for its sustained automatic fire and ammunition commonality, but its weight, reliability quirks in harsh environments, and aging design have driven the search for a successor. 

Its long service record reflected both its genuine utility and the tradeoffs inherent in any weapon built to do one job: put a lot of rounds downrange, and it did that very well. 

The M249 fulfilled a need for decades. I carried one at times and found it to be a good weapon. There were issues, but overall, it was reliable and provided good firepower. But its time has come. I hope to get some time with the M250 soon, the new kid on the block.