Category Archives: Weapons Technology

Name That Round!

Hey, don’t be surprised if it throws you. It sure threw us, and we thought we knew guns and ammo!

Need a hint? It’s .30 caliber, and a bit of a Frankenstein monster with a rebated rim and a sharp shoulder.

Need another? It was created as a deer-taking round, gerrymandered to fit a unique state law.

Give up? Explanation after the jump.

Continue reading

Homebuilt Innovation: Ultra Light .22 Bolt Repeater

This is a remarkable home made survival-type .22 rifle that is chock full of ingenuity.

It may be amateur made, but its builder, who posts on YouTube as ECCO Machine, has professional equipment, and, more importantly, skills. Most parts of the rifle are machined from billets of aluminum, titanium, and ABS plastic. The barrel is a carbon-fiber-wrapped .22 barrel liner. The bolt is made of machined titanium alloy with a welded-on handle, and it has a rare feature in a rimfire rifle, forward locking lugs.

The resulting rifle is ultralight: less that 1 lb. 3 oz. The featherweight rifle stows itself into a package less than a foot and a half long.

Unlike most amateur’s adherence to the material or materials, and process or processes that they know best, ECCO Machine’s practical use of a range of materials and methods is something worthy of a major manufacturer. Plastic, carbon fiber, aluminum, and titanium are all used in places where they’re most suitable.

The only steel or stainless-steel parts are the sear, striker, spring, screws, the barrel liner only, and a modified Savage stainless mag (with a really clever and dead-simple retaining catch that is its own spring).

The bolt’s forward locking lugs lock into a barrel extension, as in an AR; the barrel extension is also made of titanium. The rifle is readily taken down without tools. Everywhere the solutions chosen show both imagination and a practical turn of mind. For one thing, he came up with a really clever way to manage the cartridge feed by making the ejector do double duty.

There’s a really neat surprise in the grip (which he doesn’t count against the gun’s 18.9 oz weight) and the carbon-fiber stock can hold up to 40 .22 long rifle cartridges. There is a nifty titanium front sight base modeled on the classic AR FSB, and a special threaded muzzle cap that’s part of the rifle folding/stowage mechanism. (An alternate threaded adapter can convert these fine threads to the threads needed to attach a suppressor).

This video shows many more details of this intriguing firearm.

One of these should be built into ever ejection seat on every combat jet. Heck, we should build one into the RV-12.

There are several other interesting amateur builds on ECCO Machine’s YouTube channel. Hat tip, Hrachya at TFB.

Thump with TRUMP (No, this is NOT political)

Not the least bit political… this is an entirely different TRUMP. The guy getting sworn in Friday is Trump. TRUMP, all caps, means Training Re-Usable Mortar Projectile, and here you see a demonstration of unboxing a live M2 60mm Mortar, setting it up, and setting up TRUMP rounds and firing them.

The propellant and the on-target pyro charge are 20 gauge shotgun shells loaded with black powder. Strict limits on powder weights must be observed, lest your TRUMP rounds cross the threshold where they’d become unregistered Destructive Devices, a felony violation of the National Firearms Act. This limits the range of the mortar and the spectacle of the rounds’ detonation, but it can’t be helped. The mortar itself is a registered Destructive Device, and in the USA that is handled under the NFA like a machine gun or silencer would be, requiring ATF registration prior to possession, and a $200 transfer or manufacturing tax.

“Yeah, but,” we can hear you thinking out loud, “Where are you going to get a mortar?”

They’re around, but if your local gun store is fresh out, try the guys who made the video, Ordnance.Com. They have a website and a YouTube channel, but they also have M2 mortars just like this one and TRUMP rounds for sale on Gun Broker.

They also have 81mm TRUMP rounds, and older-style 60mm inert, reusable rounds. You can use the 60mm rounds in any 60mm mortar, and the 81mm rounds in any 81 or 82mm mortar.

TRUMP. Make Artillery Great Again.

Wednesday Weapons Website of the Week: Liberated Manuals

We’re going to be the soul of brevity on this one, because there’s no magic here at Liberated Manuals, it’s just one more source of public-domain military manuals.

They describe their raison d’être as follows:

This website is a comprehensive source of government manuals, in PDF format, free to copy, republish and distribute as you want. The goal of this website is to “liberate” government manuals from the dirty hands of CDROM selling mafia. All manuals are offered at no charge.

Sure, it’s an ugly and basic website, but on the gripping hand, it’s free stuff. What’s not to like?

There’s a list and a search function at the home page. Some of the manuals include (these are all .pdfs):

And one of our personal maintenance favorites:

There’s a lot more than just gun manuals, though. Go there and take a look around!

Kyle Defoor’s Range Gun “Inventory”

For the last week-plus, top instructor Kyle Defoor has been posting his “inventory” on his Instagram account, one a day. Our Traveling Reporter, a Defoor trainee and admirer, if not outright fan, has been linking them to us, one a day, and we’ve been waiting to assemble them and give you a single overview. Here it is; this is what’s in a single top instructor’s battery these days.

His training battery comprises eight guns, some used frequently and some for special purposes. There are four ARs (all BCM, which he endorses), two Glocks, one bolt rifle (Remington 700), and one DA/SA pistol (SIG 229 Elite). For each one, he painstakingly records the details down to the scope mount and slings and holsters, and he answers some reader questions, so for any gun that interests you, go to the linked Instagram page.

The AR Rifles

They’re all from BCM, with whom Defoor is in a committed relationship, as they say. BCM also provides the iron sights for those rifles that have ’em, and Viking Tactics (VTAC) the slings. There are a selection of calibers and lengths for specific purposes.

The most-used AR is this 11.5″ 5.56 mm Short Barrel Rifle (SBR), which is used 18-20 weeks a year for both military and civilian contracts.

The accessories include interchangeable red-dot and scope optics in Bobro mounts (Aimpoint Micro T1 and US Optics SR4-C respectively), the Streamlight Protac Rail 1 with an Arisaka Defense light mount, and a Gemtech flashhider for use with the G5T. The US Optics scope is their short-range 1-4 variable, which is presently off the market as the company overhauls its short-range line; its nearest military issue equivalent is the Elcan Spectre DR, which is not continuously variable. The SR4-C is an ingenious design, with a mil reticle (several options) on the first focal plane, which keeps the mils accurate with magnification, and a 4-moa red dot on the second focal plane. (There is an excellent five-part review of this scope at the Austin Police Marksmanship Team blog. Begin with Part 2 if you’re in a hurry; Part 1 is the justification for using a scope on a patrol carbine. Then click the left arrow to read subsequent parts).

Used 18-20 weeks a year for military contractcs and for some civilian carbine classes. My scope and Aimpoint share the same mounting slot on my top rail for ease of switching depending on what the customer wants.

Note that this is the baseline AR of a pro, and it’s run on an XM177-length barrel, probably suppressed more often than not. That’s a reflection of what’s happening in special operations units, not just in the US military, but worldwide.

Here’s a longer-barreled 5.56 AR used about 6 weeks a year for military and civilian scoped rifle classes. The barrel is 16″ stainless steel with 1/8 twist rifling and a mid-length gas system. The scope is a US Optics variable 1.8-10 power in a Bobro mount.

The Gemtech suppressor he uses with this rifle is the G5T; the rest of the accessories are the same as his other ARs.

Here’s a baseline .300 Blackout gun.  It’s got a 9″ button-rifled barrel. This one is used a few times a year for “specialized military contracts,” and is set up with a Gemtech flash hider for The One silencer.

What seems to be “the usual” KD4 accessories: BCM flip-up sights; VTAC Sling;  Aimpoint Micro T1 on a Bobro Mount; Streamlight Protac Rail 1 with an Arisaka Defense light mount. One thing this carbine has got that the others haven’t is a cleaning rod secured to the rail with zip ties.

And finally, this one’s just for hunting. It’s a 16″ .300 Blackout rifle with a 1/8 button-rifled stainless barrel, and has similar accessories to the other ARs.

The scope is the US Optics variable 1-4 power Dual Focal Plane on (what else?) Bobro. Kyle says he uses it to take deer, coyote and wild boar.

The Precision Rifle

This rifle is a modified Remington 700 with a 7.62mm NATO 20″ 1/10 heavy barrel, threaded for use with the Gemtech Sandstorm suppressor.

The mods/accessories include: a KRG stock and bolt lift; VTAC Sling; US Optics 1.8-10 variable power scope, with the Horus H25 reticle, mounted in Badger rings; and the ubiquitous bipod from Harris Engineering. Defoor uses it for military contracts 4 weeks a year.

I can’t express how happy I am with the KRG stock. It makes a stock 700 about .5 MOA tighter throughout the spectrum of the caliber compared to an OEM buttstock and is LIGHT! The weight thing matters when I’m humping long distances for FTX’s and evals. Additionally, KRG has accessories that are smart, lightweight, easy to install, don’t cost an arm and a leg and work WELL! This is expected from KRG since their owner is a mil snipe with experience like myself. I have no affiliation with KRG but if you’re in the market for anything bolt gun you should give them a look before they take off and get super busy,

Listen up to that recommendation, precision shooters: Defoor has a pretty good track record at flagging the Next Cool Thing before it gets cool.

The Pistols

The fundamental pistol of Defoor’s battery is the G4 Glock 19.

His regular carry gun is used for almost all classes, and apart from his own sights and his (Raven Eidolon) or Safariland holster, the only thing not stock Glock is the barrel, a KKM.

I’ve been using match barrels in Glock pistols for over 10 years now. I started using KKM’s somewhere around 2010 or 11 — long before it become the popular barrel of choice it is now. I also used Wilson combat match barrels for Glocks back when you had to fit them. I prefer hand fitting a barrel because I can make it even more accurate.

But he recommends you be in no rush to replace the barrel:

I tell everyone my opinion is to shoot the Glock pistol stock and wait to get a match barrel when you notice groups starting to open up a bit. In my experience this happen somewhere between 80 and 100,000 rounds.

In case you were wondering why Tier 1 units that shoot obsessively day in and day out went to the Glock, a lot of the answer is packed into that paragraph above. He also points out that the match barrel is match, not magic:

A match barrel will not help you magically shoot better all of the sudden. All it does is hone good fundamentals a little more. The average difference that I have measured over tens of thousands of shooters between a stock barrel and a match barrel at 25 yards on an NRA B-8 bull is somewhere between 3-4 points or around an inch tighter- both of these metrics are with a 10 round group from the standing unsupported position.

For about four weeks a year, for certain military contracts, he uses this older G2 G19, set up with a very unusual sight: an Aimpoint Micro on a Raven Concealment Balor mount. This one has had fewer rounds through it and still has a Glock barrel.

Sometimes he’ll just mount this slide on a G19 frame that allows a weaponlight or weapon laser. Same holsters; but he has some interesting observations on the Aimpoint vs. the more common pistol red dot, the Trijicon RMR.

If you want to go the route of a red dot on a pistol using an Aimpoint Micro will give you faster results in performance than an RMR. This is due to the Aimpoint being a tube and an RMR being a flat plane red dot. I’ve had great success and starting people off with a set up like this and then transitioning them to an RMR later.

I’ve assembled dozens of guns like this one for people who are older and whose eyesight just does not allow them to shoot irons affectively anymore — it’s amazing to see the reaction of people when they can shoot and perform the way they did 40 or 50 years ago. The Micro is definitely harder to conceal and will require some adjustments of clothing and belt type, along with a quality holster like mine. Safari land 6000 series holsters can be easily modified with a Dremel to hold this set up and still maintain retention. There are multiple reasons for MIL/LE to use this setup, although I recommend to all of our clients to issue two slides; one setup like this and one with traditional sights.

Sounds like we need one of these, or a trip back to the eye surgeon. (May not be an option. Our guy, the brilliant Dr Jack Daubert of West Palm Beach, has unfortunately had to retire).

Finally, there’s the SIG 229 Elite, which is used with organizations that use SIGs, or other DA/SA guns rather than striker-fired, and that don’t have a loaner gun for Defoor to use himself while conducting training.

Nothing magical here, just a pistol. About the only unusual thing here is that he got Raven to make him a one-off holster for the gun.

I also will sometimes use this when I’m training units that shoot a Berretta 92 when they can’t supply me with one (I don’t own a 92).

And that wraps up one instructor’s training and defensive battery. Instead of having many guns (either in quantity or in battery) he has stuck to basic platforms, and plowed his efforts into training instead. There’s a lesson in that if we want to pick up on it.

Update

This post has been corrected. Kyle’s main go-to Glock 19 is a G4, not a G3 as we erroneously reported. We regret the error. -Ed.

Homesmithing News: Printed Revolver, Easy Home Rifling

Here’s the Imura Works’ latest Zig-Zag Revolver, the Flying Swallow. Imura Works is named for the Japanese martyr to the cause of home gunsmithing.

It has quick-change cylinders for rapid reloads.

Of course, this wouldn’t be that interesting if files weren’t available. But files are available — how ’bout that. The file pack includes not only the .stls that you need to print it out, but also assembly drawings that show how it all goes together.

Happy printing!

Beyond Printing: The Steel Rifled Barrel

Of course, a printed pistol has its limits; we’ve seen a lot of better examples of homemade guns made from steel. In an austere or denied environment, raw steel will always be available, but one stumbling block many small and home machinists have encountered has been rifling a barrel. But it turns out, there is a high-throughput, benchtop way to do it: electro-chemical machining (ECM). You don’t need a big ECM machine: you can improvise with innocuous parts and chemicals (table salt!). This is the whole setup:

Yep, the el cheapo battery charger is all the power supply you need. They used 33 AWG copper wire.

Here’s some results from an early series of experiments.

HERE it is! Rifling a barrel using the ECM (electrochemical machining) process by the one and only Jeffrod. This fosscad project is still in its early infancy so expect more to come! ECM is like reverse-electroplating where you are removing material instead of adding it. ECM is a very precise method and is more suitable for mass production. The ECM process can be used on hard materials that cannot be machined by other more traditional processes. Unlike the EDM (Electrical discharge machining) process, no sparks are generated with ECM between the cathode and anode.

That particular barrel used a pentagonal 3D-printed mandrel, copper wires, and three rounds of 5 minutes in a saline solution with 6 volts and 6 amps running through the wires. The rifling is 5-thousandths deep. It’s not a target barrel, but it’s a process that will produce a legal and likely functioning rifled barrel. And you can experiment with it with just some steel tubing, a bucket, wires and a mandrel. This is the mandrel, with the copper machining wires attached.

The whole process is recounted on this imgur thread, including several earlier experiments before this last barrel was produced. These barrels are a proof of concept, not in any particular caliber or chambering at this time. So we’re a long way from making, say, AR barrels, but a Sten barrel is close.

 You can’t ban guns. Make one problem difficult, and the community reacts to the damage by detouring around it. Short of lobotomizing the whole community, this is only going to grow from here.

New and Better ‘Nades in the Pipeline

It looks a lot like the M67 grenade, fielded during the Vietnam War to replace the M26, which in turn replaced the Mk2 of World War II. But in fact, the ET-MP (Enhanced Tactical Multi Purpose) grenade is a whole new thing. The differences from the M67 tell the story. It’s a little larger than a baseball-sized M67; it has a different fuze that lets right- and left-handed soldiers throw it the same way; and it is a selectable grenade that can be used as a concussion grenade (called “offensive” grenades in some armies) or a fragmentation (“defensive”) grenade. The user simply rotates a selector to the letter “F” (Fragmentation) or “C” (Concussion).

“Soldiers will not need to carry as many types of hand grenades,” Jessica Perciballi, project Officer the Enhanced Tactical Multi-Purpose hand grenade at the U.S. Army Armament Research, Development and Engineering Center, or ARDEC, said in a recent Army press release.

“They are currently carrying one M67 grenade that provides lethal fragmentation effects. With the new multi-purpose grenade, they can carry one ET-MP grenade and have the ability to choose either fragmentation or concussive effects desired for the situation.”

It’s weird to see a grenade fly without the spoon flying off, that’s for sure.

The effort marks the first time in 40 years the Army has set out to give soldiers a new lethal hand grenade. Warfighters lost the capability of using an alternate lethal grenade when the MK3A2 concussion grenade was taken out of service in 1975 because of an asbestos hazard, leaving the M67 fragmentation grenade.

Another feature is that the grenades are designed for ambidextrous use, meaning that they can be thrown with either hand. Current grenades require a different arming procedure for left-handed users.

The request for a multi-purpose grenade came from the warfighter in 2010, according to Matthew Hall, Grenades Tech Base Development lead. Research began almost immediately. The science and technology funding to move forward with a project came in fiscal year 2013.

“We received direct input from the Army and Marine Corps early on, which was critical in ensuring the new arming and fuzing design was user-friendly,” Hall said.

“With these upgrades in the ET-MP, not only is the fuze timing completely electronic, but the detonation train is also out-of-line,” Hall added. “Detonation time can now be narrowed down into milliseconds, and until armed, the hand grenade will not be able to detonate.”

via U.S. Army Working on a Dual-Mission Hand Grenade – Kit Up!.

The electronic fuze means it safely can do without the grenade “spoon” that was a feature of prior American grenades. The spoon worked as a grenade “grip safety” once the grenade’s pin was pulled, only allowing a hammer to fire a primer and start a chemical time delay burning when the grenade was thrown. That was why the M67 and its predecessors were designed for right-handed throwers, and awkward for lefties. (In SF, left-handed guys would often just straighten, remove, and reverse the grenade pin, which was all kinds of forbidden, but worked just fine).

The size of the grenade was determined partly by what they had to fit into it, but also by having real, junior soldiers handle dummy grenades, 3D printed in proposed form factors.

Likewise, the test troops, deliberately selected to be average and inexperienced soldiers from a cross-section of specialties, tried many different arming control designs, and provided their input before engineers selected the final one.

In addition to its human interface improvements and frag/concussion duality, engineers have also improved the stability and shock resistance of the grenades, allowing them to be stored and shipped more easily.

Steyr / Rheinmetall Enters the G36 Replacement Competition

At least three manufacturers are competing in the evolving process of selecting the Bundeswehr’s replacement for the unsatisfactory G36 individual rifle. The participants include H&K, SIG-Sauer, and Steyr, which is partnering with Rheinmetall. (Gun history buffs, Rheinmetall is huge now, but evolved from an ancient gunmaking firm… Dreyse, of Prussian needle-gun fame). Dreyse was based in Sommerda, but Rheimetall calls Düsseldorf home today.

G36: Los! (Out with it. Here a G36E clone).

The story is told at the indispensable German defense blog, Thomas Wiegold’s Augen Geradeaus! (“Eyes front!”). Our meatball translation:

On the standing theme of the G36 and future assault-rifle of the Bundeswehr, at year’s end we’ve got a new data point: Three German enterprises will compete for the provision of the new standard weapon for German armed forces. Along with Heckler & Koch, which already supplies the G36 and has had success with the HK416 in France, and the Eckernforde-based business SIG-Sauer, the German defense concern Rheinetall is stepping in — with a weapon from the Austrian manufacturer Steyr Mannlicher. The Austrians were defeated by Heckler & Koch in the competition for the new Bundeswehr rifle in the early 1990s.

(Thomas, if you read this, you’re welcome to use any part of our translation on your site, should you want to put up an English post. We know your English is good but your time is limited, and there’s great interest in the non-German-speaking world in the Bundeswehr’s decision process).

In any event, he goes on from there to quote from a story in the Vienna newspaper Kurier, which says that Steyr is developing an AUG successor called the Gewehr bei Fuß or Foot-Soldier’s Rifle. The model being offered to the Germans is called the RS556.

The Austrian journos think that Steyr lost back in 1994 because of politics — EU Brüderschaft be damned, German officials wanted German soldiers carrying German guns. With 60% of the value added in the manufacture of the proposed Bundeswehr RS556 version being Made In Germany, they think the away team has a better shot. Our translation of part of the Kurier report:

The Austrian weapons manufacturer already had a shot in Germany in 1994, when its legendary Steyr Universal Rifle AUG (Sturmgewehr 77) had the best result in tests, according to reporting at that time. Yet the German manufacturer, Heckler & Koch in Oberndorf, received the contract for 176,544 military rifles for its Sturmgewehr G36.

So what is the RS556? Essentially, it’s a reformation of the AUG’s technology into an AR-15 form factor. Indeed, at a distance, it’s hard to tell it from a SIG or a 416. So however this shakes out, the AR is going to notch up another win. From the same Kurier report:

The new RS556 indeed looks like an American weapon, but it is the further development of the Steyr Sturmgewehr 77. With just a handgrip and no tools the barrel can be changed. Ther eare three barrel lengths available, and the rifle can be employed as assault rifle, submachine gun or light machine gun according to length.

You may recall this was a selling feature of the AUG, although not one that seemed to be prized by end users. It looks like the Steyr RS556 is also fully ambidextrous.

Due to a special surface coating, the rifle also works without gun oil, which is an especially large advantage in desert operations. The gas system and the rotary-locking bolt are inherited from the earlier StG 77 (AUG).

The AUG had some success, arming Austria, Australia (in a local version; bad news for ill-educated Yanks who always confuse those entirely different countries), some of the UAE forces and (briefly, because nobody paid to maintain them) the US Immigrations & Customs Enforcement agency. (ICE now uses M4s in either semi or surplus configuration, which have mostly replaced the late lamented AUGs and the not-as-lamented MP5s).

When The Army Resisted the M16A2, Part 3 of 3

The previous two stories set the stage, for a look at a report drafted for the Army Research Institute for the Behavioral and Social Sciences the Army was still pursuing the “best” (an upgraded M16 meeting all Army objectives) instead of the “good” (the M16A2, which was developed and revised to meet Marine objectives). Of course, we all know the spoiler aleady: the Army accepted the Marine M16A2 as is, leaving the report as an orphaned artifact. The report is here: http://www.dtic.mil/dtic/tr/fulltext/u2/a168577.pdf

Colt factory shot of the M16A2. The A2 was developed by the USMC, but was manufactured by Colt and FNMI.

This is the third of a three part series. In the first part, Thursday on WeaponsMan.com, the Army contractors noted the specific solutions implemented on the A2 and the problems the Marines solved thereby, but complained that the problems and solutions were too USMC-specific. In the second part, posted yesterday, we discussed just what they thought was wrong about the Marines’ product. In this, third, part, we’ll list the modifications that they suggested in lieu of or in addition to the A2 mods.

Most of the Army’s problems with the A2 related to the burst mechanism, and the sights, especially the complicated rear sight. (This is actually an A3/A4 or M4: note the knobs, left, for removing the carrying handle. The A2 handle was forged as part of the upper receiver.

Reliability

We should note that the Marines’ tests, as reported in this document (p,7), demonstrated significantly lower reliability, and increased fouling in the A2 compared to its older brother. These tests are suspect because the early lot of XM855 used was considered bad ammo, but the M16A1 did outperform the A2.

Thirty Ml6A1 rifles firing 26,010 rounds of M193

Failures to fire – none
Failures to feed – 3 (Not locking magazine in place)

Thirty M16A2 rifles firing 26,010 rounds of XM855

Failures to fire – 52 (27 – bad ammunition) (25 – mechnanical [sic] malfunctions)
Failures to feed – 3 (Improperly loaded magazines)

Those failures to fire that were not attributed to bad ammo were thought to be caused by the A2 trigger system’s Achilles’s heel, the burst trigger mechanism. The A2 performed even worse in a cold weather test, but again, it was with the questionable ammunition, and many of the failures to fire were also laid at the feet of the burst mechanism.

The report has an interesting discussion of the burst mechanism and its rationale in Marine, but not Army, small arms doctrine:

The M16A2 has less combat capability due to the elimination of full automatic fire. Full automatic fire enhances the ability of Army units to clear and defend buildings, to conduct final assaults on enemy positions, to defend against an enemy final assault, to conduct an ambush, to react to an enemy ambush, to engage an enemy helicopter or fast moving vehicle, etc.

While the Marines claim greater accuracy and conservation of ammunition for the 3-round burst control, no data were generated during the test to support these contentions and no supportative [sic] data are known to exist.

Also, it should be noted that room-to-room fighting was conducted with blanks, no close-in firing was conducted, no firing with short time limits was conducted, no firing at aircraft was conducted, etc. In other words, for all of the automatic/burst firing conducted during the test, a semi-automatic mode of fire would have probably resulted in a greater number of target hits.

Finally, to be given very serious consideration, is the fact that the burst control requires nine (9) new parts in the lower receiver, evidently contributing to the large number of weapon malfunctions during testing of the M16A2.

They also took issue with the heavy barrel (“heavy in the wrong place”), the twist rate (preferred 1:9), stock length increased when even the A1 stock was too long for small soldiers, and the fast twist’s incompatibility with the .22 subcaliber system. 

The article includes an extensive comparison of the pros and cons of Marine KD vs. Army Trainfire marksmanship modalities. These training differences result from the different combat envelopes for the rifleman: the Marines need to engage with rifles in the 300-to-800 meter space, because they don’t have the supporting arms that the Army can count on, at least, not in the same quantity. A unit that must fight with just its organic weapons needs to get the very most out of these weapons. The Army of 1986 did not consider a 500 or 600 meter target a primary rifle target, but a crew-served-weapons target.

In the end, the recommendations the contractors made were mostly about the sights. They put their recommendations in a table with the M16A1 and M16A2 stats. Since the latter are probably familiar to most readers, we omit them now to save time, and just show the contract recommendations.

Item Recommended
Front sight (day) Fixed blade, 0.090″
Front sight (night) Luminous dot on each sightguard
Rear Sight (day) single 2mm peep. A single elevation knob marked for 200, 250, 390, 25, 400, 500, 15, 600, 700, and 800 meters. Windage knob at rear. Each click equal to 1 MOA
Rear Sight (night) Two luminous dots on upper portion of receiver (or a single flip- up luminous dot located forward of the carrying handle) are aligned with front dots for shooting at night
Zero Recording Yes
Zero Inspection Yes
25m setting (day and night sights) Yes
Mechanical Zero Yes
250-m battlesight Yes
Firing mode Semi and Auto
Barrel 20″. Slightly heavier than A1 at receiver and mid-barrel. 1:9″ twist
Handguard Same as M16A2 except held in place with a securely fastened ring nut to provide rigidity.
Buttstock Same material as M16A2. Same length as M16A1. Option for adjustable length.

There are several interesting observations to make here. First, the contractors recommended that the Army make changes that would decrease the mechanical accuracy of the proposed M16Ax relative to the Marines’ A2. Specifically, these changes included the wider fixed front sight blade, the 1-MOA adjustments on the rear sight (A2 offers ½-MOA), and arguably the simplification of the rear sight. The trade-off was simplicity and ease of training, instead of superior bullseye performance.

Second, some of the proposals would definitely improve the utility of the firearm, including restoring the short stock, or replacing it with an adjustable one; increasing the barrel diameter towards the chamber rather than the muzzle, thus improving sustained fire accuracy and reliability; reverting to automatic fire from the burst mechanism (which also has side benefits, in improving the trigger’s feel and consistency). The night-sight proposal was truly ingenious.

Third, in some of these road-not-taken proposals, the Army was reverting to the original AR-10 design and rejecting changes that were largely imposed on the AR design by the Army in the previous decade. These include the rigid fastening of the handguard, and the fixed front sight blade.

Finally, these proposals were almost the last gasp of the iron-sighted military rifle. As this  document passed from the contracting officer to file cabinets across the service, without action, special operators were already wringing out scopes and single-point sights, and a few visionaries were already arguing that the day of the iron sight had run its three centuries, and was now at an end. A new generation of optical technology was eliminating the two objections that had kept optics off the rifles of most soldiers: less durability than irons, and slower target acquisition. Many men’s efforts went into winning over the Voices of Experience who still said “no” to anything with a lens, thanks to memories of Uncle Joe’s elk lost because his scope fogged up, or the VC that got away because somebody attached an unauthorized 4×32 Colt scope to the carrying handle of his M16.

When the Army Resisted the M16A2, Part 1 of 3

The M16A2 was adopted by the Marines in 1983, and then by the Army three years later, but all of its development was done, largely on a shoestring, by the Marines.

For example, the finger bump on the A2 pistol grip? The very first prototype was built up by a Marine officer on an A1 grip, using plastic wood or body filler! Most of the modifications to the A2 were aimed at:

  1. Increased practical accuracy;
  2. Increased effective range;
  3. Increased durability; and,
  4. NATO compliance (adopting a NATO round equivalent to the FN SS109 round).

In a brief overview of the service life of the M16 series for American Rifleman in June, 2012, Martin K.A. Morgan encapsulated this history well:

In November 1983, the U.S. Marine Corps adopted a product-improved version of the M16A1 chambered for the 5.56×45 mm NATO round. The new rifle was called the M16A2 and it differed significantly from its predecessor: improved rear sights, a brass deflector, a heavier barrel and 1:7-inch rifling were among the changes. The M16A2 also replaced the M16A1’s “AUTO” selector setting with a “BURST” setting delivering three rounds with every trigger pull. The Army followed the Marine Corps’ adoption of the improved rifle in March 1986 when it ordered 100,176 M16A2 rifles from Colt. In September 1988, the U.S. government placed an initial order for 266,961 M16A2s with Fabrique Nationale’s North American subsidiary, FN Mfg., Inc. of Columbia, S.C. Late the following year, when 57,000 U.S. military personnel conducted the Operation Just Cause invasion of Panama, the M16A2 was used in combat for the first time.

For practical accuracy, the A2 had new sights, with a square front post; for range, a new round with a heavier bullet, and new rifling to match; and for durability, new stocks and handguards and significant metal reinforcement in the lower receiver’s weak areas, the pivot pin bosses and buffer tower.

The rifle was not without controversy in the Army. Indeed, contractors for the Army Research Institute for the Behavioral and Social Sciences examined the rifle and concluded that, as their paper’s abstract notes:

[U]se of the M16A2 rifle by the Army would be extremely problematic, a-fact due, in part, to the vast differences between the marksmanship training philosophies of the Army and the Marine Corps.

(The paper is here: http://www.dtic.mil/dtic/tr/fulltext/u2/a168577.pdf)

The Army had been researching improvements to the M16A1 for years, but hadn’t actually implemented any. In the foreword to the Army Research Institute paper, the word “problematic” crops up again and one gets the sense that the problem was this solution was Not Invented Here, and moreover, not developed the way the Army wanted to develop one. 

Referring to earlier research, they wrote:

A detailed evaluation of M16Al performance was conducted to determine adequacy, peculiarities, etc. The findings clearly indicated that the M16Al was an adequate combat rifle; however, many shortcomings were identified that should be addressed in a new rifle or any rifle Product Improvement Program (PIP).

They considered that the improvements in the A2, listed below, were suitable only for the peculiar circumstances of Marine Corps service.

The Marine Corps test results stated the following advantages for the PIP [Product Improvement Program -Ed.] rifle:

  • Ease of training (handling and ease of sight movement).
  • Improved safety (no hazard when adjusting elevation on the rear sight even with loaded weapon).
  • Increased effectiveness at long ranges (more hits, better accuracy, and greater penetration).
  • Improved handling characteristics and durability in hand-to-hand close combat.
  • Reduced barrel jump and muzzle climb during automatic and rapid fire.
  • Increased contrast and less glare with square front sight post.
  • Stronger, more durable and improved grasping characteristics of front handguard.
  • Stronger barrel with quicker twist to take advantage of increased effectiveness provided by new ammunition.
  • Improved sighting characteristics providing quick target acquisition for moving targets and better detection of targets in low level light conditions at close ranges, and more accurate long range fire by use of two modified rear sight apertures.
  • Increased ammunition conservation and more effective use of ammunition with burst control device.
  • Conformity to human factors standards by lengthening stock (alleviating bruised eyebrows, noses, and lips).
  • Stronger, more durable stock.
  • Stronger, more durable buttcap which also reduces slipping on the shoulder during firing.
  • More controllable and comfortable pistol grip contoured to the shape of the hand.
  • Improved brass deflector which protects left handed shooters from hot ejected brass casings.
  • Can use NATO type improved ammunition (XM855) which provides improved performance and penetration at long ranges.

The Army evaluators were impressed by that list of solutions, but thought they all traced back to four specific USMC objectives or requirements:

The above list of advantages is very impressive. It appears that the rifle meets the primary requirements stated by the Marines:

  • A sight adjustable to 800 meters.
  • A bullet with better accuracy at 800 meters and the capability to penetrate all known helmets and body armor at ranges of 800 meters.
  • A rifle with more durable plastic parts and barrel which will take a beating during bayonet training and extended field exercises.
  • The replacement of the full automatic capability with a burst mode which fires a maximum of three rounds with each pull of the trigger.

…but they thought that the requirements were too Marine-centric.

The list, however, represents the objective and subjective evaluation of Marine Corps personnel who are emphasizing the most positive aspects of rifle characteristics as they pertain to envisioned Marine Corps requirements.

This is the first of a three part series. In the second part, tomorrow on WeaponsMan.com, the Army contractors damn the A2 with faint praise and list a litany of A1 shortcomings that they believed that the A2 did not resolve. In the third part, the modifications that they suggested in lieu of or in addition to the A2 mods are enumerated.

As it was, the contracting officer’s representative approved the paper in February, 1986. In March, and probably before any of the responsible officers read the paper, the Army went ahead and adopted the M16A2, just the way the Marines had shaken it out.

That makes this paper a time capsule.