Tag Archives: firearms

Competition Meets Tactical: SOCOM and the Vortex Razor HD Gen II 1-6x

I love competition shooting, and I love modern military gear. Sometimes, the two worlds collide, and I always find such events fascinating. Let’s take a look at optics used on carbines.

Right now, the gold standard, go-to optic for three gun shooters is the Vortex Razor HD Gen II 1-6x. It provides excellent glass clarity, 6x magnification for long shots, a simple reticle that’s easy to work with, a wide field of view, a very forgiving eyebox, and a bright center dot for close-in stages all at a price point much more reasonable than a lot of its competitors. When it came out, it undercut the previous standard (the Swarovski Z6i 1-6X) by about $1,000, and money saved is ammo to practice with. Between the glass quality and the eyebox, on 1x it works a lot like a red dot, and the scope body basically disappears.

There’s always a catch though, and the catch for the Razor is the weight. It weighs 25 ounces, about ten ounces more than the Z6i. And that’s not including a mount for either. With a mount, you’re looking at almost two pounds of weight added to your gun. For 3-gun, it doesn’t matter, because stages aren’t that long. You shoot, dump your gun, move on. And lots of guys have a carrier for all their stuff when they’re not running through a stage.

The weight sucks to carry, but that’s also a lot of capability. SOCOM also loves the Razor. They love it so much they had Geissele make them a mount for that exact scope. It really fills a need that they’ve been looking to fix for a while: to get the benefits of a red dot and magnification in one optic.

Red dots are great, because they simplify aiming. Dot goes on the target, shoot. There are no sights to align. And because of the way the human eye perceives the dot, it appears in the same focal plane as the target. So you can maintain a target focus and still get accurate hits.

The only downside to dots is that they don’t give you any magnification. Aimpoint red dot optics were in use as early as Operation Gothic Serpent,1 where it quickly became clear that the one shortcoming of the dot was that it didn’t help with target identification. If a terrorist is in a crowd, he probably is dressed like everybody else, and magnification helps spot the small differences that give him away. An ACOG sight will help with this, but it’s got fixed magnification, and a tight eyebox, so it’s going to be slower than a red dot.

The Razor gives you all the benefits of both, plus enough durability to withstand the lousy operating environments and abuse that soldiers tend to inflict on their gear, all at a reasonable cost.2 The only penalty is weight.3 And that’s a price they’re willing to pay.


  1. I.e. “Black Hawk Down” over in Mogadishu. 
  2. I don’t know what Uncle Sam gets his for, but on the civilian market a Razor HD Gen II can be had for about the same price as a 4x ACOG. 
  3. When mounted in Geissele’s excellent mount, about 30 oz. or 1.88 lbs. 

AR-15 Innovations Roundup

Normally when I see innovations in the AR-15 market, they come in the form of a component that can be easily combined with others. Something like BCM’s KMR handguards that used a magnesium-aluminum alloy or Proof Research’s carbon-fiber-wrapped barrels. These are cool products, but they can still be used by enterprising homebuilders like yours truly. So I’m not usually impressed by a lot of the premium AR-15 builders out there, simply because I can do something similar, and I enjoy putting AR-15s together. Your mileage may vary of course. You may be happy to pay someone else for labor. However, there are some manufacturers making some innovations to Stoner’s design that are much less easily integrated into homebuilds. Something where they’re willing to push the envelope and offer something new. Let’s look at a couple.

Knight’s Armament E3 Bolt
A standard AR-15 bolt uses eight square lugs. The lugs are square because of manufacturing processes available at the time the rifle was originally designed, but any engineer will tell you that corners tend to focus stress.1 As a result, the standard replacement interval for a bolt is 5,000 rounds (or so). Your bolt may last longer, but that’s the usual interval that the manufacturer suggests. Knights changed this by rounding all of the lugs, as seen in this picture. A standard bolt is on the left; the E3 bolt is on the right. Both have extractors removed.

ar-15 bolt comparison

Now, this has the downside of requiring a nonstandard barrel extension to work. So you’re stuck with Knights’ barrels. Not that those are bad barrels. On the other hand, the bolt life is expected to exceed that of the barrel. In Ballistics radio’s endurance test of an SR-15E3, they put 20,000 rounds through without cleaning or bolt breakage. The E3 bolt is available on all current Knights Armament rifle builds.

There are other proprietary things in the SR-15 design, like a nice ambi lower and an intermediate length (longer than midlength, shorter than rifle-length) gas system, but these can be had elsewhere, and have been done by others. The SR-15 is a pretty complete package but the coolest part is that nifty bolt.

Cobalt Kinetics C.A.R.S.
Cobalt Kinetics makes some really nice looking rifles. But lots of people have some CNC wizards to mill cool things out of billet aluminum, and if you choose handguards and receiver sets from the same manufacturer, you can get (or make) other cool looking rifles too. On some of their higher-end rifles, they have the C.A.R.S. system, which is aimed squarely at the competition shooter. When you’ve fired the last round from your magazine, the bolt locks open, just like on a regular AR-15. But the empty magazine also drops free automatically. No mag release press required. And when a fresh magazine is inserted, the bolt goes forward to chamber the next round automatically. This system can be disabled with a switch, and there are still the regular magazine catch and bolt release on the lower. This system requires some hand tuning during assembly, and is only offered on complete rifle builds. And yes, they’ll do custom colors if you like.

I love to see companies pushing the envelope and offering a product that stands out from the crowd.


  1. Ask the DeHavilland Comet 

Marine Raider Regiment Declines the M27

I’m a big fan of the AR-15 platform and of HK’s version, the 416, which became the USMC’s M27 IAR. The USMC really like the M27, and has moved it from being the squad automatic weapon to also being the squad designated marksman’s weapon, and soon to being the standard weapon for every man in the fireteam. But the Marine Raider Regiment has declined to get in on that, saying they’re happy with their existing M4s. Let’s unpack this a little bit. I’ve long held that while the HK 416 is a good weapon, it doesn’t do much that a well set up M4 doesn’t.

The Marine Raider Regiment1 is a special forces offshoot of the Marine Corps. So it’s under the auspices of SOCOM, not the regular Marine Corps. In terms of equipment, it gets to pick from it’s choice of stuff that SOCOM approves of and stuff from its parent service branch (i.e. the USMC). Previously, the carbine choice would be between USMC-standard M16A4s and M4s or the SOCOM M4s. Being a smaller group with a much greater ability to get new stuff, SOCOM has nicer M4s than the USMC does. Or Big Army for that matter.

M4s configured through SOCOM channels will probably have the following features: safe/semiautomatic/full automatic trigger group instead of the safe/semiautomatic/burst trigger group, a medium-weight barrel profile instead of the “government” barrel profile, and a longer, free float handguard. For the handguard, it will likely be either the Daniel Defense M4 RIS II quadrail2 or one of Geissele’s Mlok handguards.3 Either way, that’s most of what you get in a 416, other than the short-stroke gas piston system. At best, this would be a lateral move, to a new weapon system that doesn’t get you much else4, and is heavier to boot.

The M27 is also a little bit longer (16″ barrel on the M27, instead of a 14.5″ barrel on an M4A1). Which doesn’t sound like much, until you add a suppressor. And the Marine Raiders always run suppressors. Adding the suppressor length gets you back to the approximate barrel length of the M16. Longer is a little more awkward indoors, and the Raiders have mentioned that as another reason why they like their M4A1s.

None of this is all that surprising to me, but it’s always nice to see someone else confirm one’s analysis.


  1. f.k.a. MARSOC. 
  2. I discussed this rail in more detail in my M4 PIP post
  3. Discussed here
  4. In my post comparing the M4A1 PIP and the HK416, I talked a bit about how long each weapon can sustain a cyclic rate of fire. 

Improving the AR-15: Colt Canada At Bat

I’ve mentioned before that the AR-15 is a really great design. It got a lot of things right. It’s very hard to compete with a design that has had 60-odd years to fix bugs and get improvements. And when it’s not an AR-15 design that’s winning, it’s often a derivative. The popular HK416 is just an AR-15 with a few improvements that HK likes. Let’s look at another improvement project, courtesy of Colt Canada.1 Unlike the HK416, which you can buy today, this is a notional project.

colt canada rifle

Colt Canada has had a license to manufacture and sell Colt AR-15s (and derivatives) for quite some time, and their C7 rifle is basically an M16A1E1, rather than an M16A1 or M16A2. The C8 is very similar to the M4. Colt Canada also uses excellent hammer-forged barrels, which they make in-house.

Our first major difference is the handguard integrated into the upper receiver. Colt Canada already makes these for their IUR and MRR product lines. An integrated handguard is simpler, more rigid, and may be lighter depending on the design. It does lock the user into one type of accessory attachment system and handguard configuration, however. It also means that the handguard has to be designed cleverly to allow access to the gas block and the barrel nut.

Next, we have an integrated suppressor built into the barrel. Very cool. This should save some weight and length over attaching one on the end of a barrel. It also requires careful design to allow the suppressor to be easily cleaned in the field. Colt Canada discussed the finer points of this rifle design with the USMC, who are big on suppressors. I’m stoked about that, because I’m also a huge fan.2

The last is the power-pack in the stock, combined with a powered accessory rail system. Centralizing the battery should be a net improvement in weight, plus it means there’s only one battery to worry about. On the other hand, it makes the rail more susceptible to the elements and a possible failure point. I’ve heard lots of stories of these projects, but I haven’t seen much actual field testing. We’ll see.

Finally, let’s discuss what isn’t changing: the operating system. Colt Canada is sticking with the same tried-and-true direct impingement gas operating system. No short stroke piston here. I’m fine with this.


  1. F.k.a. Diemaco. 
  2. Those who actually do some research will find that suppressors really aren’t that expensive in the grand scheme of things. 

Fishbreath Shoots: CZ P-09 .40 S&W ‘C-Zed’ Race Gun Build

If you’ve been following us for a while, you may remember my two race gun proposal posts from last year, in which I justified my desire to build a USPSA Limited gun on the cheap.

You may also recall the shootout post, in which I decided that the gun to buy, between the Beretta 96 and the CZ P-09, was the CZ.

Lastly, you may recall the CZ P-09 .40 review from last summer, in which I reviewed the base model gun.

We’re now nearly to the end of the series. In this post, we’ll explore what I did to the P-09 and what supporting equipment I bought, and, at the end, come up with a cost.

Requirements

Beyond the requirements imposed by the USPSA Limited rules, there are a few requirements I gave myself, too.

  1. A decent competition holster, preferably something with drop, offset, and adjustable retention.
  2. At least 60 rounds of ammunition on the belt. That was my setup with the M9, and I didn’t want to go any lower.
  3. A sturdy belt to hold everything.

Internals

The C-Zed’s guts are all Cajun Gun Works all the way. I bought their hammer, with different spur geometry for reduced single-action trigger pull, the short reset kit, which included an extended firing pin, and a number of springs: a main spring, a reduced-strength trigger return spring, reduced springs for the firing pin plunger, and an increased-strength sear spring.

The increased-strength sear spring sounds like it’s the wrong tool for lightening a trigger, pull, doesn’t it? You would be correct. Cajun Gun Works sells them as a tool for adding weight to a dangerously light trigger. I didn’t expect to need it and didn’t use it in the end, but figured that, at $10, it was worth the money just in case.

The other items on the list all work together. The hammer reduces single-action pull, the main spring reduces the work the trigger has to do, the reduced trigger return and firing pin plunger springs reduce the spring weight you’re pulling against. The extended firing pin is necessary for the lighter main springs, because the reduced hammer impulse can cause light strikes.

I haven’t had any trouble with cheap Magtech ammo, though, with the full setup. All my primers are well-punched; none are punctured.

Everything was relatively easy to install except the trigger spring. It’s a coil spring with offset legs. The trigger has two ears and a space in the middle, and a hole for one leg of the trigger spring. You have to get one end of the spring in the hole, one end on a shelf, and the trigger ears and spring coil lined up with the holes in the frame for the pin, all while pushing the pin in. It was a four-handed job at Soapbox World HQ.

In the end, the combination of modifications resulted in a smoother 7lb double-action trigger pull, and a very crisp 2.5lb single-action trigger pull (albeit with the expected double-action takeup). Those are significant improvements over the stock 10lb double-action pull, and the stock 4.5lb single-action pull. There were also improvements in crispness, creep, and reset, thanks to the Cajun parts.

Sights

Cajun Gun Works sells Dawson Precision-made sights in traditional competition configuration: blacked-out rear sights, fiber-optic front. It comes with green and red bits of fiber, so you can pick which one you want.

These were the most annoying parts to install. The Dawson rear sight was tremendously oversized, and took about half an hour of filing before I could punch it into place. The CZ factory front sight had been glued in. Try as I might, I couldn’t even begin to loosen it. I ended up stopping by the Friendly Local Gun Shop, which has a much better heat gun; they got it in a few minutes.

Not to be outdone, the front sight from Dawson took some filing to get installed, too. Precision is not an accurate descriptor of the sights’ fit into the dovetails.

Magazines

Cajun Gun Works’ part in things completed, I turned to CZ Custom for magazines and magazine wells. The C-Zed now mounts the large CZ Custom magazine well, which makes a big difference in ease of magazine insertion.

The P-09’s magazines, with the CZ Custom 140mm base plates and spring-and-follower kits, have a claimed capacity of 21. Parvusimperator suggested I take that with a grain of salt, so I assumed 20. I decided I wanted four magazines rather than just three to give me more flexibility on reloads; at the same time, I was looking to keep the total cost of the project down. I settled on four magazines with the 140mm baseplate, but only three with the spring-and-follower kit.

The end result is three magazines which hold 20 rounds of .40 S&W, and one magazine which holds 17. The latter can be used to get a round into the chamber before loading one of the 20-rounders to start a stage, and serves as my backup.

Belt Etc.

Midway USA makes a cheap two-part belt. I’m not looking for anything super-fancy, but the two-part setup is nice. I can mount all my gear on the outer belt and just velcro it onto the inner belt come match time, without having to undo any buckles. It holds my gear just fine. (That’s 1lb, 14oz of gun for those of you keeping track, plus 77 rounds of .40 and four magazines.)

Cook’s Holsters makes a decent Kydex competition holster starting at $47.95, or $67.95 if they install the TekLok and drop/offset rig for you. I had them do so. The holster is low-cut in the front, and has adjustable retention by means of a pair of screws running through springy rubber washers. The drop and offset are nice, making the draw a good bit easier.

I’ll continue to use my ten-dollar MOLLE-strap canvas Amazon-bought triple pistol mag pouches for magazine carriage. They do the job just fine; the retention straps fold out of the way easily, and on the Midway USA belt, they’re pinned in place by the inner belt.

In Sum

Here’s what I spent.

  • $506: CZ P-09 .40, night sights, 3 magazines
  • $294.60: Cajun Gun Works internals
  • $303.20: CZ Custom magazine well and magazine parts
  • $46.53: Fourth magazine
  • $104.27: Holster and belt

In total, the cost of this race gun project was $1224.60. (Or $1254.60, if you’re buying the magazine pouches too.) Even counting a trigger scale I bought and a case of test ammunition, the project tips the scales at under $1500. Has it reached the magical point of ‘good enough’? Only match experience will tell. Check back toward the end of April for some thoughts with that in mind.

Competition Meets Tactical: SOF STI 2011s

I love competition shooting, and I love modern military gear. Sometimes, the two worlds collide, and I always find such events fascinating. Let’s take a look at a little bit of Special Operations history, courtesy of an old Gunbroker auction and the late, great Weaponsman.

First, some competition background. In the USPSA Limited1 division, the dominant platform is the double-stack 1911, often called a 2011, which is the trade name used by STI for their pistols. Since STI is the biggest builder of these, and where to go for a factory-type solution, the name has stuck. While people use other guns in Limited, the 2011s are the most popular. Since it’s based on the 1911, with its expired patents, its wide open for people to play with, so you can get your gun customized to your heart’s content. While it’s the indian, not the arrow, that decides results, nobody wants to shoot a lame arrow. Plus the 1911-style, single-action, sliding trigger is super easy to make amazing. There are no better triggers than a tuned 1911-type trigger for shooting.

Around 2006-2007, one of America’s elite special operations units decided to experiment with these pistols. Here are a pair of them.
STI 40s

A few things to note. They’re chambered for .40 S&W, not 9mm NATO like you might expect. Being based on the 1911, which was originally designed around the .45 ACP cartridge, 2011s tend to be easier to make reliable with longer cartridges. .40 S&W is a bit longer than 9mm NATO, so that helps. Plus, the vast majority of 2011s are chambered in .40 for USPSA,2 that’s where most of the experience in keeping them running is focused.

From the auction description:

Both of these STI 2011 .40 caliber pistols saw actual issue and use in a US Army SOF unit in 2006-2007. One pistol is in 93%+ condition and the other is in 96%+ condition. They are consecutively serial numbered and are quite possibly the only consecutively numbered set to be offered for sale. This consecutively numbered set comes with the following items: *** individual letters of authenticity from Larry Vickers (www.vickerstactical.com) for each pistol— original, unedited versions will be provided to the buyer *** six 140mm 17 round magazines *** one 170mm 22 round magazine *** one issued Surefire X200A light *** issued Safariland 6005 light bearing holster with end user modifications *** two Eagle Industries pistol cases

These are standard STI magazines with STI follower and basepad. This doesn’t sound odd, but most competitors will swap the follower and basepad out to get more capacity. More capacity is great at a match, but it tends to make the mags a bit more fussy, and extra maintenance requirements are not the friend of the combat soldier.

What did SOF think of these pistols? They liked them, but found the maintenance requirements to be more than they wanted to deal with. Specifically, issues came up with fine desert sand from the Middle East. This makes some sense. These are tightly tuned competition pistols, built for maximum shootability. Competitors don’t mind having to do a bit more cleaning of their magazines. And of course, as a general rule, guns with a metal frame and slide need more lubrication than those with a polymer frame and steel slide.

That said, in Vickers’ letter of authenticity, he said that “these were the only pistols sold outside the unit” (emphasis added). So likely lots of the men chose to keep the pistols, because they are awesome and shoot really well. Even if they might not be the best choice for a secondary weapon out in the sandbox.


  1. No electronic sights, no compensators, no barrel porting, magazines no longer than 141.25 mm. 
  2. Because power factor. 

EXTRA: Trouble at SilencerCo?

We interrupt our regularly scheduled posting to bring you this Extra Edition. Today we’re going to get business-y and talk a little bit about problems at SilencerCo. As you may have gathered if you don’t already know, they make suppressors.

A lot of this is speculation, because SilencerCo is not publicly traded, so there are no financial statements to read. But here’s what we know:

  • They haven’t had a big, mass-appeal product for a while now. The last one I recall was the Omega.
  • Their most recent product launches are pretty niche market. One of them, the Maxim 9 integrally suppressed pistol, was definitely an R&D-heavy project.
  • Between people waiting to receive silencers that they panic-bought during the Obama administration and people waiting to hear a decisive yes/no vote on the Hearing Protection Act, the silencer market is pretty down right now.
  • SilencerCo has had a rocky relationship with Silencer Shop lately, and Silencer Shop is one of the biggest silencer retailers in the US, and certainly among the easiest to buy from.

All of the above combine to really hurt cash-flow. They desperately need a rebound product and marketing help, both of which require money. SilencerCo has been going through a few rounds of layoffs. Which might just be reorganization.

Currently, there are rumors floating around that the top three executives have been voted out by the creditors at a shareholders’ meeting. And that is starting to get troublesome. It definitely looks like trouble is coming to a head over in West Valley City.

I hope SilencerCo can pull it out, but it doesn’t look good. We’ll see how it turns out.

Resurrected Weapons: XM307

Here’s yet another attempt to replace the Mk. 19 GPMG and/or the venerable M2 HMG. The XM307 was part of the same program that gave us the XM29 OICW, and later the XM25 once the OICW failed. The program itself emerged from a 1980s study saying that weapons development had reached a plateau, and that the next breakthrough would come with the integration of airburst-fused high explosives into the US Army’s weapons. They had tried to schedule a breakthrough in the late 1960s with SPIW. They failed. Now, a new generation of engineers would try their hand.

The XM307, or Advanced Crew Served Weapon (ACSW), had the same airburst principles as the XM25 and XM29. The gunner would use an integrated fire control system to get the range to target with a laser rangefinder, set an airburst distance, and then shoot rounds at the target. Except now with automatic fire. Let’s look at a quick size comparison chart:

XM307M2Mk. 19
length52.2″65.1″43.1″
barrel length25.1″45.0″16.25″
weight50 lbs.83.78 lbs.77.6 lbs.

It’s definitely lighter. Plus, it’ll bring a flatter trajectory than the 40mm grenades of the Mk. 19, so it should be easier to score hits with. Those are pluses. And, the M2 doesn’t pack an explosive punch. All good things so far for the XM307. So let’s talk lethality.

From autocannons, we know that autocannon ammunition makers don’t think a 25mm autocannon shell holds enough explosives to make an airburst fuse option worthwhile. We know there are lots of deployed 25mm systems, so there’s plenty of incentive to try. Big market, but nobody’s bothered. This isn’t a perfect comparison, of course. Sizes may vary, but if there’s a difference, the autocannon has the bigger projectile. A 40mm Bofors fires a much bigger round than the 40mm Mk. 19. Still, it’s cause for concern.

More concern comes from the test deployment of the XM25. In Afghanistan, while there are plenty of accounts of airburst rounds scaring Taliban fighters away, there are no accounts of it actually killing anyone. And this should be its best chance for success: taliban fighters don’t wear any kind of protective gear. None. If it can’t get kills there, what about when it encounters troops wearing actual modern armor? At least the Mk. 19 has a long history of being effective against unarmored opponents. It starts somewhere. Also note that lots of comparisons with 40mm grenades make a comparison between 25mm Airburst HE-Frag and 40mm HEDP, which is going to be less effective in the pure-antipersonnel role than 40mm HE/HE-Frag.

Now, the XM307 has automatic fire capability, and a belt feed, unlike the XM25. We’re not limited to a one round for one round comparison, which means we’re going to get into “stowed kills” type computations. Clearly, the XM307 holds more grenades in a box than the Mk. 19, so we can try to come up with some notion of relative effectiveness. Or we could, if we had a lot of ammo and a proving ground. Unfortunately I don’t, and I don’t know if the US Army tried this computation. The XM307 was cancelled in 2007.

Another obvious option is to integrate the airburst fusing and targeting system into existing 40x53mm grenade systems. So you’d still have the option of using existing grenades that work, plus you wouldn’t have to develop an entirely new round and ammo system. Someone at DoD actually thought of this, and the Mk. 47 was born. It’s lighter than the Mk. 19, fires the same 40x53mm grenades, and is equipped with a targeting system to set the fuses of airburst grenades. In US Service, that would be the Mk. 285. It’s in limited use in the US Military, and has seen export success with Israel and Australia. So let’s go with that, because it’s way less cost and risk.

Verdict: Funding Denied by the Borgundy War Department Ordnance Procurement Board

Resurrected Weapons: The LWMMG

Around 2010, General Dynamics independently1 developed what they called the Lightweight Medium Machine Gun. This weapon was designed to fill the “capability gap” between the M240/MAG-58 GPMG, chambered for 7.62x51mm and the M2 Heavy machine gun, chambered for 12.7x99mm. The idea was to be able to “overmatch” enemy PKMs in a weapon that was still man-portable like an M240.

The cartridge chosen was the .338 Norma Magnum2. This cartridge was designed to fire the excellent 300 grain HPBT .338 projectiles from rifles that had actions too short to accept the .338 Lapua Magnum cartridge. It was chosen for this application for its excellent ballistic performance at range, to really allow the LWMMG to stretch it’s legs.

Clearly, the .338 Norma Magnum has a lot more recoil energy than the 7.62x51mm round used in the M240. But General Dynamics wanted to maintain portability, and their goal was to maintain the “footprint” of the M240. So it couldn’t be too much heavier or larger. To accomplish this, General Dynamics used the same recoil system they had developed for the XM806. Having the barrel, gas system, and bolt recoil together meant they could distribute recoil forces easier, and not have to use as much weapon mass to do so. The LWMMG ended up being able to use the same tripods as the M240, and is three pounds lighter than the US Army standard M240B. Later versions of the LWMMG cut two more pounds off the weight.

The US Military opted not to procure the weapon, and I don’t really blame them. While the weapon is about the same weight as the current GPMG, the ammo is heavier, round-for-round. And, frankly, the extra range over 7.62×51 is usually wasted, because of line of sight considerations or target discrimination considerations. If you are in PKM range, he is in M240 range. Or range of vehicle weapons. Or mortar range. There are lots of other ways to deal with that sort of opponent. And you’d be adding another round type and spares type to the logistics trail. The use of other weapon systems is an even better idea if the enemy comes with modern body armor.

Let’s get some numbers on the ammo weight side, since this ends up being pretty significant. We’ll look at the weight of 100 linked rounds of 7.62×51, .338 Norma Magnum, and .50 BMG. 100 rounds isn’t a basic load, but it’s a nice round number to work with. Your basic load/vehicle load will probably be some multiple of that.

  • 7.62x51mm NATO — 6.625 lbs.
  • .338 Norma Magnum — 12 lbs.
  • 12.7x99mm BMG — 29 lbs.

Can it replace other weapons? I wouldn’t use it to replace existing 7.62x51mm GPMGs, because of ammo considerations and because that range is really not needed in general. It’s wasted on the regular infantry and the training and optics available to them, plus it’s almost twice as heavy. The .338 Norma Magnum round is also entirely too powerful for a semiautomatic or select-fire Marksman’s rifle, so 7.62x51mm would stay in the inventory. The LWMMG also isn’t going to replace the M2, because you’re giving up some range and a lot of soft target terminal performance with the smaller, lighter round. To be fair, General Dynamics never proposed it as such. It’s a marvelous technical solution in search of a problem. Cool, but I’d rather spend the money on other things.

Verdict: Funding Denied by the Borgundy War Department Army Ordnance Board


  1. I.e. without a solicitation or RFP from the DoD 
  2. Not to be confused with .338 Lapua Magnum, which is a bit longer. 

Resurrected Weapons: XM806 Heavy Machine Gun

The Browning M2 is nearly 100 years old, and it is still a very effective weapon. It is heavy and made with decidedly old-school manufacturing techniques. The XM806 was an effort to replace it with a newer, lighter machine gun, still chambered for the classic 12.7×99 mm BMG round. The XM806 was a development of the cancelled XM312, which was a prospective heavy machine gun that could be easily converted to fire 25×59 mm airburst grenades.

The XM806 preserved the recoil system of the XM312 (and its grenade launching sibling, the XM307). This system had the barrel and bolt move forward when the trigger is depressed, forcing recoil forces to overcome the forward momentum of both the bolt and barrel.

The XM806 weighs only 40 lbs (18 kg), less than half the weight of the M2. It has less recoil than the M2, and it’s also easier to disassemble. On the other side, it has about half the rate of fire of the M2. For present uses, a reduced rate of fire probably isn’t a huge deal. We’re long past the days of expecting a heavy machine gun to be an effective antiaircraft gun.

While the weight savings are eye-popping, one might question the point. 40 lbs is still too heavy to easily manpack, and the weapon is still very bulky. And 12.7mm BMG ammo is big and heavy. It’s going to be a bother for a team of light infantry to deploy, and they’re probably going to be better off with GPMGs supplemented by antitank weapons, not least because of the weight of the ammo. As for vehicles, the difference between 40 and 84 lbs is basically immaterial. We can mount M2s on dune buggies. We can mount M2s on aircraft and helicopters. The weight savings really don’t get us much in terms of more usability in the roles that we normally find ourselves using a heavy machine gun. And (again) we still have the weight and bulk of ammo to deal with either way, which is a much more significant issue for small vehicles.

Probably a depressing way to look at it. But the biggest thing here would be cost, and it’s really hard to compete with an established system. When the US Army cancelled the project, they diverted funds into improving the venerable M2, and I can’t fault them for it. At least the XM312 added a new capability.

Verdict: Funding Denied by the Borgundy Army Ordnance Development Board.