As the introduction of the SIG M250 potentially opens a new chapter in the U.S. Army's squad automatic weapon story, or more accurately, the GPMG role, it is worth looking back at the excitement around the M249 when it was adopted. The U.S. Army type-classified the M249 on February 1, 1982, filling a long-standing gap in U.S. squad-level firepower.That gap had existed for decades. The issue was first addressed near the end of the First World War, when the Browning Automatic Rifle (BAR) was unveiled and remained in frontline service through World War II and the Korean War. Combat in Korea demonstrated that one automatic rifle per squad was insufficient to provide the necessary suppressive fire, leading the Army to issue two M1918 BARs to some infantry squads. By the late 1950s, however, the BAR's replacement was uncertain. The Army adopted the M14 rifle in 1957 to replace the M1 Garand, while the proposed heavy-barreled M15 variant was intended to assume the automatic-rifle role. The U.S. quickly canceled the proposed M15 program, leaving a significant gap in squad firepower which rolled into the Vietnam War. The problem became particularly apparent during the Vietnam War. U.S. infantry lacked a dedicated automatic rifle or light machine gun capable of sustained suppressive fire. The M14E2/M14A1 was introduced as an interim solution, but it never fully met the requirement, particularly as the M16 became the Army's standard rifle. The M60 was there, but not in enough numbers for every squad. Experiments with the M60 general-purpose machine gun at squad level also proved unsatisfactory. At about 23 pounds unloaded, the M60 imposed too great a burden on squad maneuverability and would reduce the amount of ammunition the gunner could carry. We are revisiting this today with the M250, as ammunition was dispersed throughout the squad to carry enough to support operations. The Army's Squad Automatic Weapon (SAW) program therefore turned toward a lighter weapon. Beginning in the early 1970s, researchers examined different calibers, including the 6mm SAW program based on the steel-cased 6x45mm and other configurations. By October 1976, the 5.56mm SAW program had become the focus, and the 6mm SAW program dropped.The requirement called for a one-man-portable, lightweight machine gun capable of delivering effective suppressive fire to 1,000 meters. Four candidate weapons entered the competition. They included the XM106, essentially a modified M16 with an open-bolt action and heavy quick-change barrel, the XM248, a belt-fed 5.56mm design with rotary drive and a dual gas system, the H&K XM262, using a roller-locked, delayed-blowback action, and the XM249, developed by Fabrique Nationale of Belgium. The XM249 was derived from FN's Minimi, first unveiled in 1974. Its selection reflected a deliberate decision to adopt a lightweight weapon based on the 5.56mm cartridge. The Army's type-classification action also included new ammunition components, including the M855 ball cartridge using the Belgian SS109 projectile and the M856 tracer cartridge.The trials used to select the M249 were extensive, as they should be. All four weapons underwent visual and dimensional examinations, parts-interchangeability testing, firing tests, environmental trials, and endurance testing. We tested the weapons with and without lubricant and subjected them to salt water, heat, tropical humidity, mud, sand, dust, rain, and icing.Ballistic testing examined accuracy, dispersion, penetration, and projectile performance. Reliability testing classified stoppages by how easily the operator could clear them. The XM249 exceeded the specified reliability levels for the less severe categories and came close to the target for severe failures.The endurance test examined reliability and durability. Reliability is a user-measured mean number of rounds between failures. There are three categories of failures: Class 1, Immediately Clearable, i.e., the gunner can clear the stoppage in 10 seconds or less by a simple action, such as re-charging the weapon; Class 2, Clearable, the stoppage will take longer than 10 seconds but less than 10 minutes to clear by the operator and may involve some disassembly and use of the cleaning kit tools; and Class 3, Severe, a stoppage the operator cannot clear by himself, such as broken parts, and which requires an armorer or maintainer. With a 95-percent confidence factor that the next specimen would perform at the same plateau as the test gun, the XM249 exceeded the Specified Reliability Levels in Class 1 and 2 failures. It came close to the Specified Levels in Class 3 failures according to MIL-DTC-70446C standards. For durability, the XM249 was expected to have a minimum 50,000-round receiver life, which we know this gun can pass with flying colors.The M249's overall performance made it the clear winner of the SAW trials. A subsequent operational test at Fort Benning reinforced those conclusions; it performed well enough that the Army decided a normal follow-on test was unnecessary. Marine Corps experiments at Aberdeen Proving Ground also produced hit-probability results that exceeded expectations. The Army and Marine Corps enthusiastically accepted the new squad automatic weapon.The M249's design combined relatively low weight with features intended to make it practical for infantry use. It was gas-operated, with a two-position rotary gas regulator offering normal and adverse settings. Its operating system delayed extraction until the rotary bolt had unlocked, helping reduce extraction problems. The weapon's welded steel receiver and internal rails contributed to smooth operation and reliability.One of its least useful features is the alternate feed. The M249 could accept disintegrating-link belts and standard M16 30-round magazines without modifications, and the normal ammunition when adopted was 600 rounds, carried in three 200-round assault packs. Compared with linked 7.62mm ammunition, 5.56mm significantly reduced the weight carried by the gunner. The M249 weighed about 15.5 pounds at the time of adoption, a substantial saving compared with the M60. But as we know, the weight increased as it was subsequently updated.Other features included a chrome-lined bore, quick-change barrel, folding stock components, a loaded-belt indicator for night use, and sights adjustable to 1,000 meters. The weapon could also be mounted on existing tripods, although squad-level employment was expected to be its primary role.Testing involving 29 XM249s saw more than 500,000 rounds fired. The M249 evaluation praised the weapon's handling, reliability, and hit capability. Its cyclic rate was approximately 750 to 950 rounds per minute, depending on ammunition, regulator setting, and fouling. The combination of portability, sustained firepower, and compatibility with the squad's 5.56mm ammunition made the M249 a significant improvement that filled a major capability gap the BAR left in 1957. While the BAR was a poor automatic rifle, it was definitely better than nothing.The M249 represented the Army's answer to a problem that had persisted since the BAR era: how to provide infantry squads with enough automatic firepower without sacrificing maneuverability. Its adoption in 1982 marked the culmination of years of experimentation and testing. When the first weapons reached troops in late 1983 or early 1984, they had finally closed that capability gap after nearly three decades. The M249 had a long service life; though some loved it and some hated it, this was partly due to poor PMCS by users and services by maintainers, and a major lack of knowledge at both levels to keep the gun running at its best. If you had a new or properly maintained M249, you had a good experience. My biggest advice to SAW gunners is to get new ejector, extractor, and feed paw assemblies, and if you can get a new barrel, that would give you a more reliable SAW, as most are in rough shape. First, the new chamber and extractor improve extraction reliability, the new ejector helps the spent brass go in the right direction, and the feed paw assembly improves feeding reliability. All of this should give you a better SAW experience. If this post has you ready to hit the range, head over to gunranges.com - a free directory to help you find shooting ranges near you, wherever you are in the United States.