Is There a Replacement for the M2 .50 caliber Machine Gun

Most of us are familiar with the M2 .50 cal. machine gun. It is found on most Coast Guard Cutters. Its familiar. Its simple. It is a stand alone weapon that requires no external power. It is frequently a Coast Guard vessel’s primary weapon, as on the 87 foot patrol boats, buoy tenders, and icebreakers. It is the secondary as on the FRCs and WMECs.

Modern-day air-cooled 0.50″ (12.7 mm) Browning Machine Gun. US Navy Photograph No. 020704-N-0156B-002.

Nominally it has an effective range of 2,200 yards, but I suspect that is only against advancing infantry formations. It is certainly not accurate at that range after the first round in full auto.

Aside from firing warning shots at close range, it is frankly not a very good weapon for use in the naval environment. The gunner is largely exposed, where he can be picked off by a sniper. Even terrorists or criminals can easily obtain weapons that equal or overmatch it range and hitting power. The damage it can do to anything beyond the smallest vessels is very limited.

When used in a crowded harbor, its range, combined with its inaccuracy, and the lack of a self-destruct feature for it projectiles, mean it may cause collateral damage.

It is almost totally useless against aircraft. During World War II, Navy experience was that it required an average of 11,285 rounds for a .50 caliber machine gun to bring down an aircraft. The .50 caliber weapons on ships were credited with 14.5 aircraft kills for 163,630 rounds expended, so it probably not going to be very useful against drones.

We should not expect it to provide an effective self defense capability.

There are things we could do to improve it. We could provide better sights. We could provide protection for the gun crew. We could mount it in a Remote Weapons Station (RWS), but really we could do a lot better.

Northrop Grumman seems to think they have a replacement, perhaps two. Most recent is the 20mm Sky Viper proposed to equip the Army’s planned Future Attack  Reconnaissance Aircraft (FARA) seen in the video above.

As with General Dynamics’ offering, specialty munitions for use against troops, unmanned aerial vehicles, ground vehicles and other helicopters, can be integrated with Sky Viper, flexibility which naturally suggests other applications.

While emphasizing that Sky Viper is a FARA-focused effort (with DEVCOM funding), Canole acknowledges that Northrop Grumman is looking beyond the platform to where it might offer a solution “with a lot more firepower than a .50 caliber”. That could include the Army’s new Mobile Protected Firepower light tank prototypes for which .50 caliber (12.7mm) auxiliary guns are already spec-ed.

“The low recoil and a relatively lightweight system really opens the door for [applications] where .50 calibers tend to be the mainstay,” Canole says.

From Back Left: 40mm grenade casing, 30x173mm (A-10/M44), 30x113mm (M230), 25x137mm (M242/Mk38 gun mount), 20x102mm (Phalanx), 50 BMG; Foreground: 300Blackout (typical rifle round), 9mmx19 (typical pistol round)

The Sky Viper, which uses the same 20x102mm round as the 20mm Vulcan Gatling gun, that equips the Phalanx CIWS, is evolved from the 30mm M230 that fires the 30x113mm. You can see in the photo above that the 20x102mm is a much smaller round than either the 30x113mm or the 25x137mm used by our current 25mm MK38 mounts, but it is substantially more powerful than the .50 caliber.

As the newest member of the chain gun family, we can expect some improvements. Compared to the M230 it has much lower recoil forces, a higher rate of fire, and is lighter, lighter in fact, than the .50 caliber M2.

Apparently earlier the M230 was also seen as a potential replacement for the .50 caliber M2. It still offers some advantages.

It is in service with the Marine Corps, so it is already in the Navy inventory and ammunition supply system. It is actually smaller, more compact, lighter, and has far less recoil than the 25mm M242 in the Mk38 mounts.

Compared to the .50 caliber, the 30x113mm projectile is far more effective against larger targets and is effective at a greater range.

Used in a remote weapon station, it is far more accurate than a .50 caliber M2, and anytime you add a remote weapon station, the ship benefits from the high quality optics that come with it.

Plus there is a programable air burst fuse already available for the 30x113mm round that is apparently effective against drones.

I would not suggest replacing the 25mm Mk38s with either of these, unless the remote weapon station also incorporated missiles like Hellfire/JAGM and/or Stinger, but as replacements for .50 caliber they offer great advantage.


24 thoughts on “Is There a Replacement for the M2 .50 caliber Machine Gun

  1. It could, but as I recall the Sky Viper was intended to replace the M296 .50BMG used on the OH-58D “Kiowa”, which weighs about the same at ~81-pounds…

      • Probably not, but the ammunition stowage itself might! The 20x102mm round is ~236.68% larger than the .50BMG…

    • Given a RWS there would probably be less ammo handling under fire and with increased accuracy and a harder hitting round you would probably need fewer rounds.

      In any case a few hundred pounds extra on a cutter is not going to make much difference.

      • On a Large Cutter no, but on a smaller one like the “Sentinel” class, where the additional weight might have an effect on the speed and range, it might…

      • The real weight difference is not in the gun or the ammunition, but in the RWS and perhaps in a need to strengthen the foundation for the greater recoil forces, but the smaller RWS have been placed on some very small vessels. The 87 foot WPBs in the Maritime Force protection units have a Remote Weapons Station (mounting a .50 cal.) along with a raised platform to mount it.

      • The ATK LW25 25x59mm Autocannon would be a better option IF weight, firepower and ammunition stowage were an issue. The LW25 weighs ~70.548-pounds while packing the punch of a 25mm round. the 59mm Cartridge would offset stowage capacity while still giving the gun the same range of the M2 .50BMG. The LW25 is based on the Swedish Husqvarna Wappen A/B M26T LIA (Lightweight Infantry Autocannon) 25x60mm…

        ( )

      • @Secundius, Thanks, that is a gun I was not aware of. The PABM information is dated from 2011 and looks like a proposal, rather than a completed project. In any case does not appear to be in the US weapons inventory, so that pretty much precludes Coast Guard use.

      • It was tested in 2008 by the US Army for their Northrop-Grumman NOC (Riverine Craft) JMEC (Joint Multi-mission Expeditionary Craft) by Aluminum Chambered Boats of Bellingham, WA., with ~35,000-rounds being fired. But as far as not being in service, neither is the Sky Viper 20x102mm or even the Lockheed-Martin/Rheinmetall GmbH-Oerlikon 35x228mm Millennium Impulse Revolver Autocannon…

      • @Secundius, We will have to wait and see if the Sky Viper is selected by any US service, but it does have the advantage that it uses ammunition currently in the US inventory. There are also other US 20mm guns a similar size. All the chain guns have been pretty successful so far, with the exception of the LW25, but it was an odd combination of machine gun and mortar.

      • The US Army toyed around with the XM25 CDTE man-portable bullpup 25x59mm grenade launcher back in 2009, and a combo replacement for the M2 .50BMG, the XM307 Advanced Crew Served Weapon in 2007 which also chambered the 25x59mm round. But could also be in thefield rebarreled with an .50-caliber in 1-minute and 42-seconds, as the XM312. The latter XM307/312 being cancelled in 2009, because the cyclic rate of fire was too low (i.e. ~250rpm) to meet USArmy requirements. And the XM25 though not being actually cancelled, funding was cut for costing to much through the Budget Control Act of 2011, in 2013…

      • @Chuck
        Unfortunately you’ve been led astray.
        The XM25 CDTE was only chambered in 20x40mm, not 20x59mm.
        It’s not surprising you are unaware of the ATK LW25 25x59mm Autocannon because it was never more than an internal prototype program from ATK, and the whole programable 25mm grenade round weapons died off when the Army halted development contracts. There was never any infrastructure built to mass produce operational quantities of 25mm programable grenade rounds. During the entire development program the 25x40mm and 25x59mm rounds were assembled by hand

        Also, it should be noted that it would not be possible to even continue the development of the ATK LW25 Autocannon, as ATK does not exist anymore. ATK became Orbital ATK a long time ago, and several years ago was acquired by Northrup Grumman. And, you can find no mention anywhere of a LW25 autocannon from NG.

        Also, the Husqvarna Wappen A/B M26T LIA (Lightweight Infantry Autocannon) 25x60mm never existed. It’s a fictitious weapon only found @ IIWiki
        Premier Modern & Future Tech Fictional Encyclopedia

        I would add that Husqvarna makes power tools, lawn mower, pressure washers, chainsaws and the like, not weapons.
        Husqvarna Vapenfabrik used to make military small arms, pistols, rifles, submachineguns, but they’ve been defunct for around 70 years.

      • Generally, I don’t think low velocity, high angle, unguided projectiles have a place as surface to surface weapon against moving naval targets,

      • Not exactly true! First generation Kel-Tec firearms were designed by Husqvarna and Chief Engineer for Kel-Tec was also employed by Husqvarna before moving to the United States…

  2. If we are going to keep a weapon crew served on deck, make it a man portable firearm whether mounted or not.

    Then look to more and better remote turrets. Use the 30mm Kongsberg turret from the ACV. Maybe the SHORADS MOOG turret. I’m really over the Mk38 at this point. Even if we up the Mk 38 its still linked amo. The remote turret uses linkless. Through inn air burst rounds and I rreally think you’d have something without busting weight margins oor penetrating the deck. Still compatible with Navy/Marines.

    • In the case of the Mod4, I think it will just replace the Mod3s.

      It may be that the Mod4s will replace Mod3s on some ships and those mod3s will be put on new cutters.

      Will have to wait and see.

  3. Pingback: “British Navy tests new .50 machine gun mounting system ASP” –Navy Recognition | Chuck Hill's CG Blog

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