Developed in the aftermath of WWII and fielded in 1957, the light and handy 7.62mm NATO caliber M60 General Purpose Machine Gun (GPMG) has been alternately praised and cursed by GIs who have carried it combat from Vietnam to Iraq and beyond.

Inspired by the WWII German MG42, the M60 was intentionally designed for mass production – cheap and fast on a stamped sheet metal receiver that houses a clever gas operated, carrier-cammed bolt mechanism first seen in the Lewis Gun of WWI.  It replaced the Browning-designed M1919 series, built on heavy riveted steel receivers with lots of machining required for its beefy, recoil operated internals.

When the original M60 is good, it is very good; appreciated for its compact size, good handling, mechanical simplicity, quick change barrel, and effective operation from shoulder, hip, bipod, tripod, or vehicle/watercraft/aircraft mounting.

But when it’s bad it deserves its ‘Nam nickname “The Pig.”  Punishing combat use in Vietnam’s tropical climate was hard on men and unforgiving of their weapons, adversely affecting all US arms which had been designed primarily for land warfare in Europe.  The M60 was lightweight, but correspondingly flimsy, prone to damage and relatively quick to wear out critical parts like the bolt and op rod.

Special emphasis on parts is called for here.  With spares and replacements supplied in later decades by unevenly performing, lowest-bid subcontractors, the gun itself can’t be blamed for problems arising mostly from user abuse, poor maintenance and extreme environmental conditions.

Despite its handicaps, the Sixty performed rather well when light weight and mechanical simplicity were preferred vs. the heavy M1919 series .30 caliber guns.  Determined to phase out all those old Brownings, the Army began a series of modifications to the basic M60.  The M60D came first, a helicopter door gun characterized by its spade grips and prominent ring sight.  The solenoid-fired M60E2 was developed about the same time, a coaxial gun for tanks and helo gunships.

The M60E3 followed, dropping five pounds in a major overhaul demanded by the Marine Corps.  Easily recognized by pistol grips fore and aft and a receiver-mounted bipod freed from the barrel, the weight loss unfortunately came with poor durability and reduced performance.

Over on the Navy side, SEALs liked their regular M60s, used since ‘Nam with sawed-off barrels and no front sights.  Some even utilized clever backpacks fitted with flexible feed chutes, capable of delivering a thousand rounds or more when things got particularly hairy.  Yeah, the 5.56mm Stoner LMG and the M249 SAW had their place, but there’s no substitute for hard-hitting 7.62mm rounds.  Unfortunately, the troubled E3 wasn’t up to the job.

In the early 1990s, SACO responded to Navy Special Warfare’s unique requirements and specifications, developing a retrofit parts package they called M60E4.  Quantity deliveries of new guns and E4 parts kits to SEALs and other NAVSPECWAR units began in late 1994, receiving the Navy designation MK43 Mod 0.

Still reasonably light but significantly more reliable and durable than the despised E3, SEAL Team MK43s can be recognized by a distinctive “duckbill” flash suppressor and a positive lock gas cylinder extension that is stubbier and thicker.

SAWing Off The Sixty
Over on the Army side, the 5.56mm M249 Squad Automatic Weapon began taking the automatic rifle’s place in regular infantry units in the mid-1980s.  This boost in firepower resulted in official Army doctrine being modified to reduce the number of M60s used in the traditional role of “General Purpose Machine Gun” in most infantry formations.  On the other hand, vehicle and aircraft 60s were unaffected by this ruling and continued soldiering on.

While there have been and continue to be fierce debates about the wisdom of all aspects of this, Infantry Board documentation from the period asserts that the Belgian-designed mini machine gun would make up for lack of reach and penetration with one-man portability and high volume of fire.

It is no exaggeration to say that this radical change wasn’t warmly received by all members of the infantry community.

Yes, bootborne movement to contact in offensive operations is faster with the lighter SAW, but once the firefight begins there is little to recommend using anything smaller than 7.62mm.  Same deal in defensive operations where bipod and tripod-mounted Sixties have significantly superior accuracy at longer range and decidedly deadlier terminal effect than the M249.

At the same time, users of multitudes of aging M60s in tanks, helos and other tactical platforms were developing serious envy for their counterparts in the US Marine Corps.  Leathernecks were beginning to get another Belgian designed weapon, the 7.62mm M240, marveling at its astonishing reliability and durability.

Against this background, sufficient pressure was brought to bear in favor of retaining a 7.62mm belt fed weapon for infantry combat.  But the burning question was which medium machine gun would be best?

The process of finding an answer began with Fort Benning’s Dismounted Battlespace Battle Lab (DBBL, commonly pronounced “dibble”) preparing a detailed list of what the ideal weapon would have to do.  This drove specific requirements for technical testing at Aberdeen Proving Ground and more general operational testing at Fort Campbell.

Trial by Fire: Sixty vs. 240
The Army’s big 7.62 belt fed shootout kicked off in January 1994 under the interesting program title of Medium Machine Gun Upgrade Kit.  This name actually fits rather well because the only two significant competitors – M60s and M240s – were modified versions of weapons currently in the Army inventory.

SACO’s “Enhanced” M60E3 guns were fitted with a number of product improved parts and the FN 240s were coaxial guns from M1 Abrams tanks, converted for dismounted ground combat with buttstocks, bipods and such; hence the “Upgrade Kit” moniker for both.

Each manufacturer submitted eighteen guns and more than a year of technical torture and tactical trials ensued.  This ended in December 1995 when the Army declared the M240 victorious.

Not surprisingly, there were strong critics of the decision then and now, raising objections and citing shortcomings in the process with varying degrees of credibility.  Sadly, by keeping a close hold on details of the test regimen and tabulated results, the Army hasn’t helped dispel inevitable misinformation.

What is a matter of public record is the much-cited test results table quantifying two key performance areas; Mean Rounds Between Stoppages (MRBS) and Mean Rounds Between Failures (MRBF).  Stoppages are jams and failures are parts breaking – both are essential indicators of combat serviceability.

50,000 rounds were fired through both the M60 and the M240.  The 240 was a runaway winner in averaging 2,962 MRBS and 6,442 MRBF.  The Sixty limped along at 846 MRBS and 1,669 MRBF.

Determined to find and report more facts of the matter, we went right to source, Program Manager Soldier Weapons at Picatinny Arsenal.  Naturally, our first request was for hard copy of test documentation.

Sorry, came the official answer, “We can’t release any test paperwork until your request goes through legal.”  Seems the specter of defamation lawsuits still looms darkly even after a dozen years have past and even where tabulated test results speak for themselves.

OK, we pressed, how about an interview with Ed Malatesta, the individual who was Product Director/Program Manager for the process?  Although since retired from government service, as luck would have it he’s now an independent contractor working at PMSW.  A phone interview was agreed to and arranged by officials in surprisingly short order.

In a conference call and subsequent email exchange Malatesta was very emphatic on the following:

SADJ:  What major factor(s), in your opinion, led to the decision to phase out the M60 in favor of the M240?

Malatesta:  Reliability was by far the major factor.  The M60s were always breaking and this doomed them almost from the beginning.

SADJ:  How is this shown in program documentation?

Malatesta:  In data reporting the various test results.  Based on this, the Army Source Selection Authority, a general officer, wrote in summary, “In view of the above discussions (Reliability, Probability of Hit, Human Factors and Price) and based on an integrated assessment of the above findings (Developmental Tests, Operational Tests, Human Engineering Testing and a Price Assessment), I conclude that Saco (M60) has no reasonable chance for award and should be eliminated from the competitive range, and that a competitive range of one, Fabrique Nationale Manufacturing, Inc. (M240) be established.”

Our candid discussion with Malatesta, coupled with additional research, clearly shows the fundamental problem that, in his words, “doomed” the Sixty.  Put aside all the “Enhanced” M60E3’s niceties of lighter weight, portability, balance, controllability in assault fire, easy to parachute with, already in the inventory, tons of spare parts, existing instructional materials, lots of experienced armorers, etc., etc.: SACO’s Sixties broke down way too often while FN’s 240s didn’t.

And the Army moved out smartly to fully equip the force with a new machine gun that – despite being considerably heavier – was vastly more reliable.  When you need it to shoot, it shoots.