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.


“BAE Systems Successfully Tests APKWS Laser-Guided Rockets Against UAS” –Seapower

An artist’s conception of an APKWS strike against an unmanned aircraft. BAE SYSTEMS

The Navy League’s on line magazine, Seapower, report the successful test of a new alternative for countering Unmanned Air Systems.

BAE Systems Inc. has successfully tested APKWS laser-guided rockets in precision strike tests against Class 2 unmanned aircraft systems at Yuma Proving Grounds, Arizona, the company said Oct. 11.

The 2.75-inch test rockets combined standard M151 warheads and Mk66 motors with APKWS precision guidance kits and a newly developed proximity fuze, enabling them to engage and destroy airborne drones at a fraction of the cost of traditional counter-UAS strike capabilities.

(A Class 2 UAS is 21 to 55 pounds, operates at 3500 ft or lower, and has a maximum speed of 250 knots, so its pretty small. ScanEagle is an example.)

As important as this cUAS capability may be, adding this capability to Coast Guard Units would also have the bonus of providing both a capability against a range of surface targets from small, fast, highly maneuverable craft to small ships, and at least a basic anti-aircraft capability.

Adding a launcher and the required laser designator to vessels with Mk 38 mod2/3 gun mounts should not be too difficult. The PATFORSWASIA Webber class FRCs would a good place to prototype an installation.

More on APKWS here:

New 30mm Mk38 mod4?

The video above has a segment, beginning about time 4:55 to 5:25, that may be of particular interest to the Coast Guard. It appears that the Navy may finally be moving from the 25mm gun to the 30mm in their next iteration of the Mk38 mount.

We have known all along that the 30mm is more effective for Coast Guard type missions. Apparently the Mk38 mod2 was adaptable enough to except the 30mm but the Navy did not seem interested. Despite earlier indications the Mk38 mod 3 would be significantly different, including use of the 30mm, when it immerged, it retained the 25mm.

I suspect the combination of the UAS threat and the availability of a programable air burst round may be what has gotten the Navy’s attention.

For our purposes, in addition to the air burst round, the 30mm does have a greater selection of projectile type including “swimmer round” designed specifically to counter Fast Inshore Attack Craft (FIAC).

More on the New 50mm Chain Gun, and Maybe Counter-UAS

“marauder2048” included a link to this DOD Ordnance Technology Consortium web page in a comment on my earlier post, “Remember the ALaMO,” noting a contract to conduct a “Demonstration Against Unmanned Aerial Systems (UAS) Targets” using the 57mm ALaMO round. But looking through the web site there were some other contract awards that I found interesting, including indications the 50mm program is still progressing. The list includes contracts for both FY 2020 and FY2021.

The following 50mm contracts, totaling $64.39M, were awarded to ATK (Northrop Grumman) in FY2020.

  • Aug. 2020, 1904 INIT 4096 B, 50 x 228mm High Explosive Airburst, Traced (HEAB-T) Munitions, $44.30 M
  • Sept. 2020, project 1904 INIT 4104 B, 50 x 228mm Target Practice Munitions, $20.09 M

The following 50mm contracts were awarded to GD-OTS, General Dynamics Ordnance and Tactical Systems, in FY2021:

  • Oct. 2020, project 1904 INIT 4051 B, 50x228mm Programmable Airburst Ammunition – EMD, $46.42 M
  • Oct. 2020, project 1904 INIT 4052 B, 50x228mm Target Practice Munitions – EMD, $17.62 M
  • March 2021, 1904 INIT 4050, XM1203 50mm x 228 Armor Piercing Fin Stabilized Discarding Sabot with Trace (APFSDS-T) Cartridge Engineering and Manufacturing Development (EMD), $25.20 M

There are some interesting awards in other categories as well. There are these contracts for 30mm systems that do not appear related to the 30mm Mk46 currently in the USN inventory. These sales, late in FY2020, could be for foreign military sales:

Then there is this:

  • Apr. 2020, 101 INIT 0865, Counter Unmanned Aerial System (CUAS) 40mm Proximity Sensor, Electronics Development Corporation (EDC), $4,628,000

This is apparently in reference to the 40mm Mk19 Grenade machine gun, which is, I believe, on the PATFORSWA Webber class WPCs. This could mean it is to be used as a hard kill system against small Unmanned Air Systems, though the Mk19, with its very low muzzle velocity, seems a strange choice for an anti-air weapon.

40 mm Mark 19 on USS Hopper DDG-70 in September 2006. Note the 25 mm Mark 38 in the background. U.S. Navy Photograph 060906-N-9851B-002.

Video: Northrop Grumman Showcases Very Light Weight Torpedo At Sea Air Space 2021″ –Naval News

Our friends at Naval News have an update on the Very Light Weight Torpedo program. It seems to be progressing rapidly. Apparently this is seen as an urgent requirement.

The discussion in the video talked about the anti-torpedo and anti-submarine capabilities, but no discussion of use against surface targets. I suspect this is because those capabilities are the primary selling points for the Navy. It may not be that it is incapable of attacking surface vessels, which should be easier targets.

We talked about this weapon earlier, in greater depth, including potential Coast Guard use.

Full scale production should drive to price down to a point, it might even find its way into the Coast Guard.

(There does seem to be an error in the written portion of the Naval News post in that it says the diameter of the weapon is 121 mm while the video discussion indicates 171 mm. The figures I had seen earlier were:  6.75″ in diameter (171.45mm), about 85″ in length, and weighs about 220 pounds or about 100 kilos).


Bahrain Bound FRC gets Upgrades, LRAD and Short Range Air Search

(As we get into this, you may want to click on the photo to get an enlarged view.)

This Spring, the first two Webber class patrol craft are expected to go to Bahrain to start replacing the six 110 foot WPBs of Patrol Force South West Asia (PATFORSWA).  Two more will join them in the Fall and the last two in 2022. Back in 2018, I speculated on what might be done to modify them for duty in this more dangerous area. Apparently the Coast Guard leadership has had a few ideas of their own.

We have some very shape observers among the readers of this blog.

First Andy provided the photo of USCGC Charles Moulthrope (WPC-1141) above and pointed out the Long Range Acoustic Device (LRAD, the gray device mounted near rail on the O-1 deck just this side of the port forward corner of the bridge) and the four round sensors a short way up the mast two on each side. I note these systems were not on the ship when it was handed over by Bollinger (photo below).

The 41st fast response cutter (FRC), Charles Moulthrope, as delivered to the Coast Guard in Key West, Florida, Oct. 22, 2020. It is the first of six planned FRCs to be stationed in Manama, Bahrain. (U.S. Coast Guard photo)

Then Secundius identified the four round sensors on the mast as Sierra Nevada Modi RPS-42 S-Band Radar.

From the Company web site: “RPS-42 is an S-Band tactical hemispheric air surveillance radar system. It is a member of the non-rotating, solid-state, digital radar family Multi-mission Hemisphere Radar (MHR), developed by RADA Electronic Industries Ltd.
“The RPS-42 is a pulse Doppler, software-defined radar platform, that can detect, classify and track all types of aerial vehicles – including fighters, helicopters, UAVs, transport aircraft, etc. at tactical ranges. A single radar platform provides 90º azimuth coverage. Hemispheric coverage is achieved when four radars are employed as a system. Mobile or stationary, the system can be integrated with any C⁴I system and other radars and sensors. The software is able for On-the-Move (OTM) Operation. The radar can operate either as a stand-alone or as part of a large-scale surveillance system.
“The Antenna is an Active Electronically Scanned Array (AESA) based on Galliumnitrid (GaN) Amplifiers. Its diameter is 50.4 cm , the max width is 16.5 cm. (19.8″ x 6.5″ –Chuck)
“The achievable range for detection of the smallest drones (known as Nano UAV) is 3.5 km”

These radars use Galliumnitrid (GaN), the new technology in radar, that allows the AN/SPY-6 to significantly outperform the earlier AN/SPY-1 found on most Aegis equipped warships. (Reportedly a 3000% improvement)

You can get an appreciation of what this is about from this Popular Mechanics article. This Is the ATV-Mounted Jammer That Took Down an Iranian Drone.

There is more here: Light Marine Air Defense Integrated System [LMADIS] (

I’m only guessing, but I would think the FRC would also have the same or equivalent complementary equipment as the LMADIS, e.g. small EO/IR camera, Skyview RF Detection system and Sierra Nevada MODi RF jammer (Photo below, I may be seeing the jammer–pictured below–located above and behind the port side RPS-42 radar arrays, visible between the radar arrays and the tripod legs). The cutters of this class are already normally equipped with electro-optic devices, both on the mast and on the Mk38 gun mount, which can provide a kinetic counter to UAVs.

Sierra Nevada MODi RF jammer. From the company web site, “SNC’s Modi II is the most modern & highly-capable dismounted EMC system in the DOD inventory.”

This was probably what the Commandant was talking about, when he said that Coast Guard PATFORSWA had a counter UAS role in a recent interview.

I am thinking, this radar might also be used on some of our other cutters as well, perhaps the 210s and the six 270s to be FRAMed, to provide them better control of their helicopters on approach in bad weather. The 210s have no air search radar and the 270s will almost certainly lose the Mk92 fire control system which provides their only air search radar currently. Reportedly the radar has a range of up to 30km and an instrumented range of 50km at altitudes from 30ft to 30,000 feet. Apparently the Marines are also using it to direct fire for their short range air defense systems. which includes a 30mm gun and Stinger missiles.

Thanks to Andy and Secundius for kicking this off.

“Here Is What…Missiles Actually Costs” –The Drive

The Drive brings us estimates of the per round price for several types of missiles in the US inventory, “ship launched” here and “air launched” here. The “air launched” list includes a couple of missiles that can also be surface launched, LRASM and Hellfire. I have pulled out info on those systems that could someday up-arm Coast Guard cutters.

These numbers might look quite scary at first glimpse, but if you consider the cost of an operating day, for a ship like the $650M National Security Cutter, (I don’t really know, but a very rough estimate would be on the order of –don’t quote me– $250,000/operational day, see foot of the post for how I got this) it does not look that much out of line. (Reportedly the 57mm Mk110 gun cost $7.2M and the rounds $1200 each. The fire control systems, maintenance, training, and support personnel are additional cost.) By comparison, the Hellfire looks like an absolute bargain. We could probably mount a set of up to eight on an FRC for less than the cost of a 25mm Mk38 mod3.

Keep in mind, that if the Navy sees a need to arm Coast Guard cutters, the Navy pays for the systems. (I do believe the Navy does not really understand or appreciate our counter terrorism needs, maybe the Coast Guard does not either.)

We had some earlier estimates of the cost to arm cutters here, here, and here.

Evolved Sea Sparrow Missile (ESSM) – $1,795,000 (average for the entire projected Fiscal Year 2021 purchase, which includes ESSM Block I and Block II versions).

Mk49 “SeaRAM launcher for Rolling Airframe Missiles.

Rolling Airframe Missile (RAM) – $905,330 – This unit price is an average across the full projected Fiscal Year 2021 order, which includes multiple RAM variants, including the Block II and IIA.

Tactical Tomahawk (TACTOM) Block V – $1,537,645 (base land-attack variant). Conversion kits to transform Block V missiles in Block Va Maritime Strike Tomahawk (MST) anti-ship missiles approximately $889,681.

The U.S. Navy littoral combat ship USS Gabrielle Giffords (LCS-10) launches a Naval Strike Missile (NSM) during exercise “Pacific Griffin” on 2 October 2019. The NSM is a long-range, precision strike weapon that is designed to find and destroy enemy ships. Pacific Griffin is a biennial exercise conducted in the waters near Guam aimed at enhancing combined proficiency at sea while strengthening relationships between the U.S. and Republic of Singapore navies. U.S. Navy photo by Mass Communication Specialist 2nd Class Kenneth Rodriguez Santiago

Naval Strike Missile (NSM) – $2,194,000 (Navy only requested funds to purchase 15 of these missiles in the 2021 Fiscal Year budget).

ARABIAN GULF (Sept. 16, 2018) A MK-60 Griffin surface-to-surface missile is launched from coastal patrol ship USS Thunderbolt (PC 12). Ships attached to U.S. 5th Fleet’s Task Force 55 are conducting missile and naval gun exercises against high speed maneuvering targets to advance their ability to defend minesweepers and other coastal patrol ships. U.S. 5th Fleet and coalition assets are participating in numerous exercises as part of the greater Theater Counter Mine and Maritime Security Exercise to ensure maritime stability and security in the U.S. Central Command area of responsibility, connecting the Mediterranean and the Pacific through the western Indian Ocean and three strategic choke points. (Photo by MC2 Kevin Steinberg)

Griffin – None included in current budgets, but  2019 Fiscal Year unit cost  $127,333. 

ATLANTIC OCEAN—A Longbow Hellfire Missile is fired from Littoral Combat Ship USS Detroit (LCS 7) on Feb. 28 2017 as part of a structural test firing of the Surface to Surface Missile Module (SSMM). The test marked the first vertical missile launched from an LCS and the first launch of a missile from the SSMM from an LCS. (Photo by U.S. Navy)

Hellfire (AGM-114):  A number of different costs were reported. This is apparently due to the large number of different versions of the missile. The average price for the Navy was reported as $45,409, for the Air Force $70,000, and for the Army $213,143.

Long Range Anti-Ship Missile (LRASM)

LRASM (Long Range Anti-Ship Missile): AGM-158C Long Range Anti-Ship Missile (LRASM) for the Air Force – $3.960 million, for the Navy – $3.518 million

How I got a very approximate cost for an operational day for a National Security Cutter.

Annual Coast Guard budget approximately $12M, divide by 40,000 (approximate number of uniformed active duty Coasties, about $300,000 each), multiply by 150 (approximate number of crew members ($45M/year), divide by 180 operating day/year=$250,000/day. (Back in the 1980s I figured a 378 cost forty or fifty thousand per op day. Forget what it was exactly but the higher cost of today’s NSC sounds about right.)

New Suppressor Allows M240 Machine Gunners to Hear Orders

Soldiers at Fort Benning, Georgia live-fire testing a new suppressor from Maxim Defense on M240 Machineguns during Army Expeditionary Warrior Experiment (AEWE) 2021 which began in late October. (U.S. Army) reports that the Army is testing a new suppressor for the M240 machine gun that appears both durable and effective.

“This may be one that we recommend that a unit buy and do some sort of evaluation long-term,” Davis said. “We do know that with the gun firing, it brings the noise down. … You can fire the M240 and have a conversation right next to it.”

This May Be the Launcher We Need

Scale model of a MK VI patrol boat launching a pair of JAGM missiles. This was displayed on Lockheed Martin’s booth during Sea Air Space 2021 This illustration replaced the original 8/19/2021.

Lockheed has new vertical launchers for JAGM, the missile that is replacing the Hellfire. Presumably it can also use the Hellfire. They seem particularly appropriate for Coast Guard applications, being small enough to mount 16 missiles atop the deckhouse of the Navy’s 85 foot MkVI patrol boat. They have a small foot print and are probably pretty light. They can be mounted in multiples of quad missile launchers; each quad launcher appears to be no more than 2′ x 3′ x 8′ tall. (That is my estimate, but I think if anything they are probably smaller. The missile itself is 7.1″ in diameter and 71″ long. For reference beam of the MkVI is only 20’6″.)

The Hellfire/JASM can successfully engage a large spectrum of potential maritime terrorist threats from small fast highly maneuverable craft (with one hit) to larger ships (assuming multiple hits), helicopters, drones, and some fixed wing aircraft.

There are two naval versions, one for mounting directly on deck and one for mounting below decks with just the muzzles above deck.

These would be an excellent addition to the Webber class being sent to replace the 110s in PATFORSWA. Probably could fit one or two quad launchers forward of the deckhouse on the Webber class on either side of the 25mm Mk38.

Thanks to Malph for brining this to my attention.