Tag Archives: firearms

NSWC Crane Likes Midlength Gas Systems

These days the US miltary favors M4s with 14.5″ barrels and carbine-length gas systems, which is to say, a gas port located approximately 7.8″ in front of the bolt face. It works. On the civilian market, lots of companies are offering (usually pinned) 14.5″ barrels with the midlength gas system, i.e. gas port about 9.8″ ahead of the bolt face. Civilian shooters will tell you the midlength gas system is a softer shooting system. But is it more reliable? We could make arguments about it, but NSWC Crane decided to put it to the test.

Barrel Wear: Accuracy Degradation
In a normal, carbine-length gas system, a degradation of accuracy can be seen after about 6,000 rounds. Crane’s testing found that after 12,000 rounds, the midlength barrels did not suffer appreciable accuracy degradation.

Muzzle Velocity
Does the midlength gas system cause any loss in velocity? In the unsuppressed case, the carbine had a mean muzzle velocity of 2,905.4 feet per second, and the midlength had a muzzle velocity of 2,906.4 feet per second. The difference in means is -1.0 feet per second, or 0.04%.

In the suppressed case, average muzzle velocity was 2,989.7 feet per second for the carbine system and 2,983.0 feet per second for the midelength. Here the difference is 6.7 feet per second, or 0.23%. In either case, muzzle velocity is negligible.

Terminal Velocity (100 yards)
Given the negligible difference in velocity at the muzzle between the carbine length and midlength gas systems, we would expect the difference at 100 yards to be similarly negligible. And it is. In the unsuppressed case, carbine-length gas system yields a terminal velocity of 2,635.9 feet per second and the midlength gives 2,677.6 feet per second for a difference of 41.6 feet per second or 1.57%.

The suppressed case is similar, with the carbine-length gas system providing 2,654.1 fps and the midlength providing 2,686.7 fps, for a difference of 32.6 fps or 1.22%. Overall, there’s not much of a performance difference. Midlength is actually slightly better. Of course, we wouldn’t expect much of a difference in velocities from changing the gas system length.

Cyclic Rate
We might expect a change in cyclic rate from altering the gas system length (and hence the gas pressure in the system). Also, small reductions in cyclic rate tend to be good from a parts-life standpoint as well as a controllability standpoint. So what do we get? Again, we have the suppressed and unsuppressed cases. In the unsuppressed case, we see a reduction of 127.2 rounds per minute or 15.9% going from a carbine-length 864.8 rpm to a midlength 737.6 rpm. The suppressed case gives us a reduction of 62.7 rounds per minute or 6.9% when we go from a carbine-length 944.2 rpm to a midlength 881.5 rpm.

Stoppages
Given the reduced cyclic rate for the midlength, does this translate into more reliability? The tests showed that it did. The carbine length gas system had 65 stoppages, and the midlength gas system had 30. The high temperature (160 F) testing phase accounted for 5/65 stoppages in the carbine-length gas systems and 1/30 stoppages in the midlength gas systems. Low temperature testing (-60 F) accounted for 27/65 stoppages in the carbine-length gas systems and 15/30 stoppages in the midlength gas systems. All other stoppages occurred in ambient-temperature testing.

So now we have some hard data proving that midlength gas systems are better on 14.5″ barreled weapons. Great! This gets more interesting because the USAF is looking at buying 50,000 improved M4s for security forces, battlefield airmen and OSI. That’s the kind of significant buy that can have an impact on what kind of weapons the rest of the US armed forces use. Remember, the Air Force were the first to embrace the M16.

Movie Guns: Bond’s Walther PPK

Quite possibly one of the most famous movie guns ever, the Walther PPK has been (generally) Bond’s sidearm since his introduction to the silver screen in 1962. It probably doesn’t need much introduction, but I’m going to give it one anyway.

The 7.65 Browning (.32 ACP) Walther PPK replaced the .25 ACP Beretta 4181 as Bond’s sidearm in the novels starting in the book Dr. No. A fan, Geoffrey Boothroyd, had written Fleming disapproving of this small choice of firearm (in the Beretta). They corresponded for a while, and after establishing that Fleming thought Bond should be armed with a semiautomatic pistol, eventually settled upon the Walther PPK as the new firearm.

As a brief aside, I hate the Walther PPK. I can’t stand it. The trigger is garbage. The sights are virtually nonexistent. The mag release is in a stupid place. The grip is entirely too small for the hands of any reasonably-sized man. The slide seems purpose-designed to tear up the web of your hand. I would say at least it’s pretty, but there are plenty of other pretty guns out there that aren’t a total soup sandwich to shoot.

Now, because James Bond is a franchise but his weapon remains basically unchanged, we’re going to look at this first in the context of 1962 when the first movie was made. We’ll also look into it as a choice today.

1962
Much as I hate to admit it, the PPK is not a bad choice in 1962 given Fleming’s strict criteria. There are not a lot of small semiautomatic pistols available. My preference would be to either relax the semiautomatic requirement and carry an S&W Centennial Airweight, chambered for .38 Special, or to relax the size constraint a bit and carry a Colt Commander2, chambered for 9mm. In either case, I get a much more effective round and a much more shootable weapon. Most of the time, Bond has a great concealment garment on. This does require a bit more effort on the part of one’s tailor, but that is why one employs a tailor.

2018
You must be joking. There are so many better choices in 2018 that it truly boggles the mind, and it gets even worse if you relax those constraints again. In the Profoundly Small Semiautomatic category, we have the Glock 43, S&W M&P Shield, Walther CCP, and SIG P365. Also the Glock 42 if we don’t mind shooting .380. If we let ourselves go a trifle bigger into double stacks, we now include the PPQ SC, Glock 26, M&PC, and P320SC, which are even better, and can take larger magazines from their bigger brothers. If you’re still packing a .32 ACP anything in 2018 and you plan on wet work, you need to have your head examined. The .380 version is outclassed both by newer, better pistols in .380 as well as the latest crop of small, single-stack 9mm pistols. In .380 right now, I’d be all over the soft-shooting Glock 42, which fixes basically every problem I have with the .380 PPK.


  1. To quote the wonderful Mr. Boothroyd, “It’s a lady’s gun, and not a very nice lady at that.” 
  2. Later called the Lightweight Commander. It’s a 1911 with a 4.25″ barrel, an aluminum frame, and chambered in 9mm. What’s not to like? 

Parvusimperator’s AIWB Experimentation

I’m not going to pretend I’m some kind of fantastic innovator. AIWB is pretty popular these days. I’m late to the party. I get it. But it’s still a decent topic, and when all of your trainer friends use it daily, it might be worth looking into. And I’m really big into experiential learning, so what the hell, right?

Let’s review our terms. AIWB (Appendix Inside the Waistband) is a mode of carry where the gun is forward of the hipbones (usually between 10 o’clock and 2 o’clock on your person). It has a number of advantages over traditional behind-the-hip IWB:

  • Better concealment

  • Faster draw time (generally)

  • Easier to defend against a gun grab

  • Much easier access to the gun when seated

At the same time, there’s an obvious bit of caution here. Clearly, we’re in the vicinity of some very important things. For some actual testing, and not just a bunch of nervous prattling, check out Ballistic Radio’s video on the subject HERE. As a bonus, this also includes some good AIWB reholstering technique to maximize safety.

Now that we’ve dealt with that annoying elephant in the room, let’s get on with it. I did need to get some stuff for this experiment. First, holsters. I wanted holsters designed with appendix carry in mind, so I hit up the good folks at Dark Star Gear for some AIWB holsters. Dark Star Gear is also the brand used in the cool video above, they’re the brand used by several of my instructor buddies who kicked off this shindig, and as a further bonus they’re local to me. I got a holster for my Glock 34 (which also fits the Glockblaster if I remove the weaponlight) and another for the Glock 17. While the Glock 17 will fit in the Glock 34 holster, I wanted to see if the reduced length of a Glock 17-specific holster mattered for comfort.

Key things I wanted in my holster were adjustable cant (I wanted to play with zero-cant and negative-cant options), and something to help tuck the gun in close to my body.

I also got a Wilderness Instructor Belt. I got the wilderness belt because lots of my instructor buddies recommended it. They also mentioned that having some kind of belt with the capability for lots of (possibly small) adjustments would go a long way to making my appendix carry experience good.

Also, note that I did not purchase pants with a waist size any larger than what I would wear if I did NOT have a gun tucked inside the waistband.

And now, a brief bit about me. I’m about average height and am a skinny dude. I spend most of my workday sitting. So sitting comfort is important to me, and the easier seated access is a nice plus. Also, my commute is roughly twenty minutes each way.

In terms of pistols, I tried my Glock 34, my Glockblaster sans weaponlight, and my Glock 17 with RMR. Here’s what I found:

  • All pistols were concealed much better AIWB than IWB or OWB with a cover garment. I could be quite discrete with even a light t-shirt as a cover garment. While my office is a pretty permissive environment, this made me feel better generally. Also, it’s pretty cool.

  • Both guns were comfortable seated at my desk or in my car. I had no complaints and wasn’t tempted to remove my gun to improve seated comfort.

  • The Glock 34-length holster made bending over a little uncomfortable. The Glock 17 less so. I don’t bend over much during the day, so this wasn’t a huge downside. Still worth noting.

  • My draw times from concealment are faster. I expect them to improve with practice.

  • My instructor buddies were spot-on about having a belt supporting a wide range of adjustments. The wilderness instructor belt is a lot more comfortable with an AIWB holster than my standard heavy leather belt, mostly because of the wider range of adjustments.

So my conclusion overall is that I really like appendix carry. It works well for me, my body type and the guns I like to carry. As with everything else, your mileage may vary. However, if you’re curious about AIWB, I would encourage you to try it out with some purpose-built gear.

On J-Frames

The persistent popularity of small snubnosed revolvers, typified by the J-Frame models of Smith & Wesson, for concealed carry purposes astonishes me. Back in the day, sure. Small, reliable, semiautomatic pistols in a reasonable defensive caliber did not exist. But this is Anno Domini 2018. It is not 1958. There are plenty of options if you want something really small and concealable and reliable and chambered in a reasonable defensive caliber. Off the top of my head, there’s the S&W M&P Shield, the Glock 43, and the Walther PPS, all with established track records and manufacturers with good QC. These are reliable choices. They’ve been on the market for years. They work. Really. And they provide so many advantages over the small revolver that I still am astonished that people go for the revolvers instead. And no, I also don’t know why my tactical friends keep seeking out training on the damn things. Let’s review the many ways that the small, single-stack semiautomatic is flat-out better than the old-school revolver competition.

  1. Sights
    I tend to get picky about my sights. Modern semiautomatic pistols allow me to be picky. There are a wide variety of sights available for your Glock 19, letting you pick exactly the ones that work with your eyesight. Single-stack subcompacts like the PPS, Shield, and Glock 43 are no different. They all have sight dovetails. This highly advanced technology allows you to change out the sights to something that better suits your needs and eyes. It’s amazing. And these small pistols from established manufacturers have a large aftermarket. You need dovetails, but you also need sights to put in them. But we have you covered with the choices above, whether you like 3-dots or tritium or fiber optics.

    The vast majority of J-frames have atrocious “sights” that consist of a little lump of metal on the front of the barrel and a little trough cut in the rear of the frame. Not adjustable, not high-visibility, not tritium, and certainly not interchangeable. Simply put, the stock sights are awful and you are stuck with them. There are a few J-Frame models that actually have dovetails, but they are tremendously expensive and there are few manufacturers working with this market niche. Otherwise, better hope your chosen rounds shoot someplace sensible based on a reasonable sight picture.

  2. Trigger
    I’ve gotten less picky about my trigger choice these days, though I still like good ones. Anyway, I can think of few things worse in a trigger than the average double action pull of a recently-made revolver. Long and heavy, and probably gritty too. Lots of people will advocate an Apex spring kit in your J-frame. Which helps. Or you could get one of those single-stack subcompacts that has better trigger out of the box. And these single stacks can also take trigger improvements, just like their bigger brethren. I’m sure if I grew up firing revolvers and figuring out how to make that trigger work well, a slightly-lightened wheelgun trigger would be the “bees knees”. But I didn’t, so it’s not. Comparing stock to stock or modified to modified, the semiautos will have the better triggers, and you’ll likely be more familiar with them, because most of your shooting is going to be with some full size semiautomatic pistol.

  3. That Wheel
    You get five shots in a j-frame. Six in some competitors. At which point you’re working with speed strips, probably. Maybe speedloaders, but those are bulky. This is a different and slower reload drill than the modern semiautomatic, which you probably spend most of your time shooting. And even the small single-stack pistols mentioned previously all hold more bullets. Also note that the J-Frame’s footprint matches that of the double-stack Glock 26, which holds twice as many bullets and can accept magazines from other, larger Glock pistols.

Just about everybody is going to be better suited to buying a small semiautomatic these days. And you’re not giving anything up on size either. Here’s an overlay from the late Todd Green, who is also firmly in the more bullets camp, where we can see that a J-frame and a Glock 26 are both about the same size.

Glock 26 j frame

Oh, and one more thing. J-frames with the locking hole in the side of the frame above the cylinder release have been known to have this lock break, jamming up the gun. Just what you want.

Soldiers’ Gadgets: Geissele High Speed Selector

The AR-15 selector is a pretty standard component. There are a few variations on the lever shape, some including an ambi part for lefties, but it’s worked the same way since the 1960s: Point the lever forward (“0 degrees”) for Safe, point the lever straight up (90 degrees) for semiautomatic, and point the lever back (180 degrees) for full automatic. Or burst. Pretty simple.

One innovation seen occasionally on competition guns is the ‘short-throw’ safety lever. This is a safety lever where semiauto requires less than a quarter-turn of the lever. Usually it’s about a 45-55 degree range of travel that will switch the rifle to semiautomatic.

Something like this has also been seen on some military rifles, including the FN SCAR. On the SCAR’s safety lever, the 45 degree position is semiautomatic and 90 degrees is fully automatic. It’s definitely easier and faster than the standard AR lever, but it’s not really worth fussing about. Unless you’re a competition shooter where every tenth of a second counts, in which case, you can mod your heart out. That said, it’s not a super popular mod on the competition circuit. Usually money gets spent elsewhere.

It becomes a little more interesting when combined with a recent Marine Corps study. The Corps appears to have (re)discovered that fully automatic fire is more effective on moving targets than semiautomatic fire. This is no surprise. We’ve known this for a while now. Recall that the original demand for the rate of fire on the MG-42 came from wanting to maximize hit probability for a target moving from cover to cover at range. And Project SALVO and SPIW were all about increasing hit probability by getting more bullets downrange.

All that said, let’s look at the specific formulation, since we have it for this study. Numbers are always good. To simulate an enemy soldier moving from cover to cover, the marines looked at a man-size target moving at a speed of about 10 miles per hour, at a range of 50-150 yards, and assumed a 2.2 second exposure. They worked out that if a soldier was firing on semi-automatic, the hit probability was about 0.4. This hit probability went up to 0.6 simply by switching over to full automatic.

Anyway, the Marines were a little concerned that by the time the soldier saw the moving target, flipped the selector to automatic, took aim, and fired, the target would be gone. Remember, there’s only a 2.2 second exposure time. So they reached out to Geissele to help. While they were wishing, they also wanted the transition in and out of full-auto to be as easy as possible.

Geissele’s high speed selector starts with a 45-degree position for semi-automatic, and a 90-degree position for fully automatic. Just like the SCAR. What’s new is that the selector is spring loaded. So the marine holds the selector in the 90-degree position with his thumb to fire on full-automatic and lets go when he wants to go back to semi-automatic.

I like the shorter throw, but I’m not entirely sold on the spring-loading. It seems to me like this is the sort of thing that one ought to be able to handle with doctrine and drill. A technological solution in search of a problem. And I really don’t think the short throw is worth the bother.

There Is No Milspec AR-10

Anytime I hear the words “milspec AR-10” my teeth get set on edge. There’s no such thing. I’m gonna repeat that.

There is no such thing as a “milspec AR-10”.

Got it? It should be pretty clear. No. Such. Thing.

Let’s start with what exactly is “milspec.” You may have guessed it’s short for “military specification,” and you’d be correct. For the US Army (and some others), they like to take ownership of certain products. Sometimes there are competitive bids. For the M4, there’s a specification of what exactly an M4 is, and then the US Army can have companies bid on how much it will cost to make a certain number of rifles to that spec. The milspec is owned by the military (in general).

So there’s no “milspec AR-10” because no major military adopted the AR-10 and cemented the design that way. Emphasis on the and. Merely adopting the rifle is insufficient. The AR-10 was used by the Sudanese, Cubans, and the Portugese, but none of those made a spec. All of those arms were built by Artillerie Inrichtigen, which wasn’t able to get more contracts and stopped making AR-10s ages ago. Still no spec.

Things got confusing in the 1990s. By that time, Eugene Stoner was working for Knights Armament, and they made the SR-25, a modern take on the AR-10 design for use as a semiautomatic marksman’s rifle. This used the gas system improvements worked out on the AR-15 and had a number of parts shared with the then-issue M16A2. The magazine design is also used in DPMS’ AR-10-pattern rifles, among others, and you can find these magazines as “DPMS/SR-25” pattern.

There’s another pattern of magazines currently in use for AR-10-pattern rifles. This one is made, confusingly enough, by Armalite. The original Armalite company ceased operations in the early 1980s. The rights to the name were bought, and Armalite was relaunched in 1996, with a new AR-10 pattern rifle (among other things). At that time the 1994 Assault Weapons Ban was in effect in the United States. This bill prohibited the sale of new magazines with a capacity of more than 10 rounds, but older magazines that held more than 10 rounds could still be bought and sold. So (new) Armalite made magazines that had a common design with M-14 magazines, so buyers of their rifle could use existing, common M-14 magazines with a couple easy modifications. These are “Armalite” pattern magazines, and they’re not compatible with DPMS/SR-25 pattern magazines.

And no, neither DPMS nor Knights nor Armalite are responsible for any current milspec “AR-10-pattern” rifle.

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.