When it’s a “rifle grip” – which is the US Army’s official nomenclature for the pistol grip on AR-series rifles, from the M16A1 which still exists in Army warehouses, to the latest M4A1 variants on the front line.
The Army has different names for many parts than the ones used by the AR community at large, or even the designers and manufacturers of the AR-15, M16, and M4 series weapons. As a result, you can be tripped up, or at least confused, when trying to follow some military maintenance procedures.
Some of these names are not really logical, and in true bullet-headed military fashion, they give the same name to several discrete parts. For example, all coil springs are called “Compression Helical Spring” (which is of course the techbical term for any standard coil spring) even though the “compression helical spring” in the buffer tube (uh, “spring receiver holder”) is quite a different thing from the “compression helical spring” that snaps the magazine catch into place.
Don’t ask me why they did that. They’re the Army. It’s their function in life to do dumb stuff.
Fortunately, they provide a terminological cheat sheet in the depot maintenance manual. The terms on the left are, if you will, English. Those on the right, Army (at least on paper. Most soldiers who work with small arms use the generic terminology). You might call it a glossary, but Big Green calls it the…
NOMENCLATURE CROSS-REFERENCE LIST
Compression Helical Spring
Bolt Catch Spring
Compression Helical Spring
Bolt Carrier Key Tool
Cam Clutch Spring
Charging Handle Assembly
Compression Helical Spring
Extractor Spring Assembly
Torsion Helical Spring
Lower Receiver Extension
Spring Receiver Holder
Magazine Catch Spring
Compression Helical Spring
Pivot Pin Detent
Takedown Pin Detent
Rifle Barrel Assembly
Fire Control Selector
Small Arms Sling
Torsion Helical Spring
Upper Cartridge Receiver
If a couple of terms completely throw you, they’re probably the names of the components of the unlovely and unloved 3-round-burst mechanism.
We’re actually not aware of any place the Army terminology is used, except for Army maintenance manuals and other doctrinal publications.
Special Agents from every other Federal Agency are snickering today, as the FBI has had to resort to a lot of begging (and a $20,000 reward, but mostly, begging) for clues about the whereabouts of two Bureau weapons pictured here (these are actually similar weapons that the FBI hadn’t yet misplaced, as of press time).
The two guns are an M16A1 updated to quasi-M4 carbine (which is a pretty typical FBI carbine), and a McMillan-stocked 7.62mm sniper rifle (again, a very typical Bureau weapon). The M16 has a carbine barrel and gas system, an EoTech sight, and a backup sight set to co-witness with the EoTech. It also has a Streamlight TL-1.
The Boston Herald has two separate stories on where the guns vanished from (on the same page!). One, a print story, quotes a Bureau official as saying that the guns were lifted from a SWAT vehicle that responded to a callout in Andover, Massachusetts. The video at the same link, from a Boston TV news report, suggests that they were stolen from the g-ride of a special agent who lives in Andover.
The FBI has an exemplary record on firearms accountability, and this sort of thing has never happened before.
Well, except for when two FBI guns like these were stolen, along with night-vision gear and body armor, from an agent’s car. That was very long ago — August of this year, in Charlotte, NC. The weapons were once again an M16A1 with Streamlight and EoTech, and a Remington 870 with pistol grip and extended magazine. (The stolen M16 also had a vertical foregrip).
And except for 2007, when some 449 weapons were lost or stolen from FBI custody, one of which was stolen from an agent’s car and then used in a Detroit homicide, and recovered at a crime scene.
But hey, that one was recovered. The Bureau will get it back… when the homicide case is concluded, if Detroit doesn’t lose it or destroy it with the tons of crime guns they stumble across annually up there.
If you’re in a position to snitch out the location of the Charlotte guns, that’s worth $5k to the red-faced G-men.
We don’t have the memo yet, but if you have the location of the Massachusetts guns, that morsel of information is worth $20k to the FBI. Apparently they take loss of a sniper rifle more seriously than an automatic weapon. (Maybe the Secret Service is threatening to bill them for the overtime their protective details pull).
The FBI has recovered the guns that were stolen in Andover, in the nearby city of Lawrence. That was quick; our congratulations to the agents involved. (To explain the cities’ relationship: Andover is the sort of place an FBI agent might live. Lawrence is the sort of place he might serve search warrants, if he’s on the gang squad). As far as we know, the Charlotte guns, and over 300 of the 449 guns from 2007, are still out there somewhere.
We don’t leave guns in cars, even though our cars reside in locked garages. We have 100% accountability of firearms. Could these facts be connected? Far be it from us to make suggestions to the FBI, who’ve been bagging criminals on a wholesale basis since Hoover (J. Edgar or Herbert, take your pick), but it does seem that they, and some other federal agencies (cough hack ATF cough), might apply a little humility and common sense to firearms storage.
While you’re contemplating the AR-10 auction we showed you this morning early, here’s a single seller whose rifles for sale include a very good collection of early Colt semi-auto SP1 Sporters. These guns have a collector following that’s only partly overlapping with aficionados of early military guns and builders of retros. For one thing, the Colts are unquestionably original factory firearms, even if they’re sadly bowdlerized compared to military AR-15s and M16s of the same period, and that alone assures them some collector interest. This is especially true of the 1964-66 very early SP1s — an SP1 serial number list has been published, which allows fairly confident dating — that this one seller has.
The gem of this stack of early Colts is this 1964 model. How do we know it’s a ’64? Oh. This is how:
VERY, VERY, VERY EARLY 1964 production original, NEAR MINT AR-15 SP-1, in the original M-16(602) configuration. “Prancing Pony” Colt logo”, “Edgewater” two piece buffer, early plastic furniture, three prong flash hider, rubber butt pad, early saftey with hole, very early push pin w/ hole, non-chromed barrel w/1:12 twist, original solid split pin FP keeper, original bolt and carrier w/large head firing pin and the RARE original CHROME BOLT.
Three-digit SP1s do come up from time to time, but not often from a dealer who’s also moving some four-digit ones, and not often in this condition:
EXCELLENT bore and chamber. VERY TIGHT fit. No magazine or box. What you see in the picture is what you get….. one of the earliest SP-1s ever offred for sale. COLLECTORS DON’T MISS THIS ONE!
We wish John well on his sales (we don’t know him, but his name’s in the auctions). At a $4600 Buy-it-Now it’s a bit rich for us — we don’t even think this morning’s AR10, a rarer and as-historic gun, will go for that — but we would not be surprised to see some collector springing that amount to hang it on his wall.
We’ll close with a backed-out picture showing the early, “dimpled” pins (which were an artifact of a manufacturing process that changed in the mid-60s), “Colt Patent Firearms” rollmarks, and the distinctive front screw-in-lieu-of-pin of the SP1 model and other early civilian-market Colts.
Pre-ban Sendra manufactured semi auto retro-mode AR-10 rifle(Portuguese contract) . Steel made lower receiver has matching serial number with an upper. Correct plastic handguard and pistol grip. Replacement wood buttstock. The gun is in excellent shape with bright and shiny bore.It comes with two original 1st generation magazines.
We have one of these on a different receiver. The Sendra receiver is machined from steel billet. It may be less authentic (the factory receivers were 7075 machined forgings) but it’s more durable; alloy AR-10 receivers, including Armalite’s and Artillerie Inrichtingen’s, are prone to a little distortion or bowing in the magwell area.
There are several differences between the Portuguese AR10s (more common, althought that’s not saying much) and the Sudanese model. The Porto AR10s have the handguards with a metal section, whereas the Sudanese ones have full-length handguards. The fiber-filled resin guards and stocks were not terribly durable, and especially on the hard-used Portuguese guns (all of which served in Portugal’s African colonies, Angola, Mozambique and Guinea-Bissau) they were often replaced by wood, either by the Portuguese Army (this one appears to be such) or by a Canadian importer.
Only the Portuguese guns had the serial numbers on the upper receiver. Contra to the statement in this auction, it is not extremely rare for a semi-auto US-market AR-10 to have the new lower’s receiver matched to the upper.
One common characteristic of these rifles is dreadful bores.
The gun is an important milestone in AR development. We’ve discussed the AR-10 a few times now. All the production guns were made in 1960-62 and most of them were used very hard. AR-10s have seen combat in Angola, Mozambique, Guinea-Bissau, the Dominican Republic in 1965, Rhodesia and Southwest Africa. They were well liked by their Portuguese operators, although parts were always a problem (the manufacturer, Artillerie Inrichtingen of Holland, went paws up and never produced any significant quantity of spares, except for hundreds of thousands of magazines).
This particular one has some valuable characteristics and one flaw. The flaw is the
The waffle mags were once common. KAC bought them all up to issue with early SR-25s, so they’re now rare and expensive. Fortunately SR-25 / DPMS / M110 / Magpul mags can be modified to work in the original AR, although most of these old soldiers are admired more than shot these days.
Now that’s a big firearms auction. We showed you guys an authenticated Battle of the Little Bighorn Springfield trapdoor carbine before the auction (and note, we may have said it was in .45-70, we think it was actually in .45-55 caliber). And it sold at the auction for $126,500. That was right in the middle of the range Julia estimated. While auction estimates are often lowballs, intended to encourage bidding, the best pieces in this auction came in within, or very close to, the estimated range — either James D. Julia’s estimates are better than average, or the market is a bit soft.
If you call a market where many exotic collector pieces find new collections at five- and six-figure prices soft.
The entire 3 days of the auction was predominantly high valued items. In fact, this auction is believed to have had the greatest number of high valued firearms; over 523 items generated $10,000 or more. 167 items generated $25,000 or more and approximately 50 items generated $50,000 or more and 9 items generated over $100,000 or more.
The overall sum achieved on the auction is staggering, but not a record… Julia set that, they tell us, with a prior auction that also sold over $18 million. But some of the unsold lots are still being bought, and yesterday the company was saying they’d grossed $17 million, so this one may yet go over the top. In addition to the Julia sales, there was a prior sale of some lots which billed an additional $3 million, so the total for this sale, which included much of Dr. Geoffrey Sturgess’s incomparable Luger collection, is over $21 million.
If you’d like to push it a tad higher, the unsold lots on which you can still make an offer are here. These are all advanced collector pieces: lever action rifles, factory engraved classics, antiques including Civil War and Federal Period muskets, and some of the Sturgess Lugers, Broomhandles and other exotica.
If you’ve been used to carrying a gun every day, you hate being without one, but frogmen have long had to either go without, or use special underwater weapons. The reason is the fundamental difference between aero- and hydro-dynamics: weapons efficient in the air are much less so in the denser medium, water. Weapons efficient underwater are hopelessly compromised on the surface. A number of unsatisfactory options for the combat swimmer include: just carrying a knife for undwerwater action; having two separate weapons; doing without armament during the underwater phase; training to bring a handgun into contact with an underwater opponent.
For quite a few years Russia has been working on a single multipurpose sub- and surface gun, which would allow them to retire their special purpose underwater weapons, like the smoothbore APS (which looks like an AK with a footlong magazine, because it’s basically an AK that fires footlong underwater spears) and a variety of pistols. While specialist publications and blogs have followed the development of the bullpup AK ADS since 2007, it’s making a splash (no pun intended) now because it was the Tula Instrument Design Bureau’s featured display at a Moscow arms trade show. To make sure you got the idea, Tula displayed it in an aquarium.
The gun uses two different kinds of 5.45mm ammo, one for limited-range underwater engagements, and one the conventional, standard Russian infantry round. As the frogman changes mediums, he changes magazines, and he’s good to hook. The rifle appears to be a bullpup AK with a few modern updates — a Picatinny rail and a 40mm grenade launcher (not the old 30mm one, although this one works on the same principles as the old one). An older Wikipedia entry has the photo of an earlier iteration that you see below (it’s expandable with a click). From this we can learn that the ADS:
Uses a standard AK-74 magazine;
is available in a suppressed version (using this at the same time as the GL, though, appears to be a Hollywood impossibility; the suppressor casing intrudes into the firing line of the grenades);
Has a Glock-style trigger safety that we believe to be a first among Russian weapons;
Appears to have rather short-radius iron sights built in;
Does have the P-rail on the carrying handle, which is the sincerest form of flattery perhaps, but kind of 1990;
Appears to have an adjustable gas system;
Appears to have a non-reciprocating, left-hand or possibly selectably-ambidextrous, non-cycling charging handle, and,
Appears to have, apart from changes required by the long trigger, classic AK lockwork, judging from the position of the pins in the receiver. This implies selective fire, with a trigger, dual disconnector, and hammer system on the same general principles used in the M1 Garand and AR-15.
There’s been a lot of media coverage of the new gun, which must please the marketing department. To us, the best general-media coverage (because it’s got the most technical information!) is this story and video at Russia Today. (If we haven’t munged the code, the video is embedded below).
Designed by Russia’s Tula Instrument Design Bureau the ‘ADS’ gun can shoot underwater using a special cartridge, which in size is suitable for the standard magazine case Kalashnikov assault rifle. To fire under water or on land, one only needs to replace the magazine of the 5.45 millimeter automatic rifle.
“Until now underwater fighters were compelled to use two types of weapon – for use under water and the Kalashnikov for overland firing. Now it is only necessary to replace the ammunition magazine,” Nikolay Komarov, head of department of foreign economic relations of the manufacturer in Tula told rostec.ru
The ‘ADS’ is also equipped with a 40 mm grenade launcher. Developers believe that its effectiveness and accuracy are comparable if not greater than the legendary AK-47m.
“The main feature of it is that the fire can be carried out both under water and on land. Currently, no country in the world has been developing such machine guns, they are developing only underwater guns,” a representative of the developer told Ria.
The weight of the machine gun with the grenade launcher is approximately 4.6 kg. The ‘ADS’ uses bullets of 5.45х39 mm at a firing rate of 800 shots/min with the aim range on a land of 500 m.
The rifle’s effective firing range underwater when using a specially designed cartridge is about 25 meters at a depth of 30 meters and 18 m at a depth of 20 m. The new underwater cartridge is externally very similar to standard 5.45×39 ammunition except for a different specially calculated bullet shape. The bullet length is 53.5 mm compared to an overall cartridge length of 57mm.
As compared to the Soviet underwater assault rifle APS that was designed back in 1970s, the new ADS is no less efficient when firing on land than a traditional Kalashnikov. Firing 5.66 mm caliber steel bolts, the APS with its non-rifled barrel is somewhat inaccurate on land. Out of water the APS’s lifetime was only 180 shots with an effective range of around 50 meters.
The new gun was displayed at an international arms fair in Moscow, Interpolitex, which has separate expo halls for cop gear, unmanned vehicle technology, physical and border security, and military equipment.
As we mentioned, it’s been around for a while, and The Firearms Blog has covered the gun’s special-purpose ammunition before, and linked to a Russian-language report with further video on the gun. (UPDATE: From the TFB report, the round appears to be a saboted, possibly fin-stabilized, penetrator and the case appears to be rebated rather than rimless. There’s more info on the ammunition at world.guns.ru — linked below). From this we learn that the acronym ADS stands for “Avtomat Dvukhsredny Spetsialny,” which meatball-translates to “dual-medium special assault rifle.” We also learn what the Russian word for “bullpup” is:
(This post has been edited to correct the invisible video. You should now have a working video window above. We regret the error).
It occurs to us that Maxim Popenker has to be all over this development, and sure enough he has been, and his page has excellent detail on the history and development of the ADS, including pictures of an earlier developmental version that shot the APS’s foot-long speargun darts, and a patent-filing image of the normal-length underwater ammo, and an explanation that it’s actually quite different from an AK:
They used the A-91M bullpup assault rifle as a starting point, retaining its bullpup layout, gas operated action with rotary bolt locking and forward ejection through the short tube running above and to the right of the barrel. Some parts of the weapon were necessarily redesigned and materials revised to work reliably when submerged in water, gas system was modified with addition of the environment selector (“air / water”). Integral 40mm grenade launcher (which fires VOG-25 type ‘caseless’ grenades using additional front trigger inside the trigger guard) is fitted with removable barrel which can be removed when it is not needed by the mission profile. Muzzle of the barrel is threaded to accept muzzle brake / compensator, tactical silencer or blank-firing adapter.
That brief snippet does not do Max’s reportage justice; go there and Read The Whole Thing™. Max’s pages on the A-91/A-91M and its non-bullpup forerunner the 9A-91 may also be of interest. Here is some information on the mechanism of the 9A-91:
The 9A-91 rifle is a gas operated, rotating bolt weapon, which utilizes a long stroke gas piston, located above the barrel, and a rotating bolt with 4 lugs. The receiver is made from steel stampings; the forend and pistol grip are made from polymer. The steel buttstock folds up and above the receiver when not in use. The charging handle is located on the right side of bolt carrier (it was welded solid on early production guns, or can be folded up on current production guns). The safety / fire selector lever was located at the left side of the receiver on early guns, but was since relocated to the right side, to clear space for the sight mounting rail. Safety / fire selector lever has 3 positions and allows for single shots and full automatic fire.
Here’s a picture of the right side of the ADS, somewhat crudely snipped from the Russian video above, with part of the selector visible at far left. You can see another reason we think the lockwork is AK-derivative. Without an ADS to examine, or maybe a .pdf manual (hook us up, Rosoboronexport, willya?) we can only speculate, of course. It does make us want to get our hands on one.
* Yes, they’re not Soviets any more, but we were going for the alliteration — and Mr Putin does seem to forget that from time to time.
We’re so going to hell for that title. But we couldn’t resist.
Here’s a bare teaser of a video from the NRA’s National Firearms Museum. We’ve never been there, but a friend who often visits raves about it. Here’s a teaser they did of one of their guns:
People often ask why the US was unique in fielding semi-auto weapons nearly universally in World War II. The only other nation that had tried to go semi-auto, Russia, retreated to bolt-action simplicity until the war was won. (In 1945, they finally introduced a practical and reliable semi-auto, the SKS-45, only to replace it within a few years with the AK, which hit mass production in the early fifties). Germany supplemented its Mausers with semi-autos, just like they supplemented their equine transport with trucks, but in 1945 the Wehrmacht was still mostly horse-drawn and bolt-action.
Japanese Type 5 semi-auto rifle in 7.7 x 58mm. This one is worth embiggening.
In Japan, they had good bolt-action rifles and decent light and heavy machine guns. One wonders how the decision to copy the American M1 Rifle was taken, and suspects it was something like Smith & Wesson’s then-CEO’s ill-starred response to Glock: “Copy the mother******!”
The Japanese Type 5 (sometimes called the Type 4) was made in small numbers. Unlike most late-war Japanese guns, surviving examples like the minty one in the Museum seem to be well-machined and carefully-finished. As you can see, the Japanese didn’t just reverse-engineer the Garand, they adapted it to Japanese training and logistics.
Dig that crazy tangent sight. And note the foreign contours of the receiver, and the stripper clip guide.
The most obvious adaptation is the 10-round, Mauser-style magazine which is loaded by two ordinary 7.7mm five-round stripper clips, a standard item in Imperial Japanese Army and Navy logistics. The receiver looks very similar, but its contours and dimensions are changed to accommodate the magazine of 10 7.7 x 58 rounds, the stripper clip guide, and Japanese machining methods. The stock shows some Japanese style, constructed of two pieces of wood joined below the beltline of the butt, and showing finger grooves in the forearm. And the rear sight’s classically Japanese, a Mauser-style tangent sight coupled with a small, high-accuracy-potential peep-type aperture. Japan’s other sighting feature was a ladder sight with an aperture of its own that coexisted with the tangent sight, and sometimes included folding lead-estimation bars for estimating lead on aircraft; we’ve never seen this on a Type 5. Few Type 5s were made (estimates range from 100 to 250), and still fewer survive (single digits). The weapon shown here is in the National Firearms Museum and is the most commonly-photographed survivor.
The NFM has a page on the Japanese long arms of World War II, which includes more photographs of this elegant gun.
This picture should answer the first question. (We don’t know the original source; if it’s yours please advise and we’ll give you credit and a link). And to explain what-all you’re seeing, and answer the second question, we have to teach youse guys some history.
(The Image has been removed, after the copyright owner identified himself in comments and asked us to do so. We have sent him a message seeking permission to restore the image (or a similar one) with appropriate credit to him, Randall Rausch, and his site, AR15barrels.com. We regret the inconvenienceto you, our readers, but we’re sure you also want to respect his rights).
The original Armalite AR-10 and AR-15 were never designed to be semiautomatic rifles: from day one they were intended to be select-fire weapons, which was the global military preference of the 1950s, while these guns were in the earliest stages of development.
When Colt modified the AR-15 design to create a semiautomatic Sporter (which went to market in the mid-1960s as the AR-15 SP1), the ATF’s Firearms Technology Branch wanted Colt to make a weapon that was not readily converted back to rock n’ roll, and that did not accept full-auto parts. And Colt took a belt-and-braces approach, modifying many parts of the gun compared to the M16 and XM16E1/M16A1 being produced for government contracts. (The sporter rifles did not cut into military production as much as you might think, because Colt used the sporter program to salvage parts that had been running-changed on the military production line, like 601 style lower-receiver forgings). The parts that Colt modified included:
Lower receiver. A 601-style forging with no retaining-pin-spring boss (the feature retro-AR heads call a “partial fence”) was used. The pivot pin location and size was changed. The pivot pin was replaced with a screw. The shelf area was not milled out enough to allow insertion of the auto sear, and the auto sear pin hole was not drilled. Some Sporters used oversize trigger and hammer pins, and so were machined to suit. Later changes to the forging and machining of the military lower, such as the full fence (guard boss around the magazine release) and machining for an increased pivot angle, were not made to the Sporter lower for a very long time. The engraving was different, including Safe and Fire instead of Safe, Semi and Auto on the left of the lower.
Trigger. The trigger was modified so that the disconnector from a select-fire or burst-fire firing mechanism could not fit into it. what was an open channel in the back “leg” of the selective-fire gun’s trigger was closed off.
Disconnector. Its tail was cut short so that it could fit in the slot of the semi-auto trigger.
Hammer. The auto hook was removed, and a notch was introduced, the purpose of which is (1) to prevent the hammer riding the firing pin down if the disconnector fails, and secondarily, (2), to jam the gun if an M16 firing pin is installed.
M16 hammer left, AR-15 SP1 hammer to the right. The hook on the upper right end of the M16 hammer engages the auto sear. The notch on the upper left corner of the SP1 hammer is intended to produce collar lock.
Selector. The selector was modified so that it had no Auto fire position, and could not be turned beyond the Semi position (labeled Fire on semi-auto guns).
Bolt Carrier. Two areas of the BC were radically milled on Colt semi BCs. The cylindrical section of the distal end of the BC, which acted in a select-fire gun to trip the auto sear, was milled off, leaving the BC significantly lighter and with a C-section rather than O-section in that area. And the area behind and beneath the firing pin — the “shroud” — was milled away. This was to allow the hammer notch and firing pin retaining collar to make contact and produce “collar lock” if an oversize firing pin is installed.
Firing pin. The semi and auto firing pin are identical except for the dimension of the retaining collar that contacts the firing pin retaining pin. The semi-auto pin is specified at .330″, and the military one was .370″. However, Colt parts during this period can be far out of spec, as much as two-hundredths out. Also aftermarket firing pins show signs of eyeball reverse-engineering; they are seldom machined to the Colt dimensions, and can have collars as large as .400″! The small firing pin collar in the semi-auto gun prevents unnecessary collar lock; installing a larger-collared firing pin risks it. Remember that collar lock if the disconnector fails is a good thing, because it prevents a runaway gun; collar lock without disconnector failure is pathological.
Upper receiver. The upper receiver of the SP1 was designed and machined for the pivot screw and can’t be made to adapt to a mil-spec lower without some kind of adapter or modification. (Silver-soldering a 7075 rod in place and redrilling the hole to the correct location and dimensions works, but the solder will not take anodizing). When the Army insisted on the superfluous bolt forward assist on its M16 variant (creating the XM16E1, later M16A1), the sporters remained “slick-sided” for many years.
The parts that Colt modified more than met ATF’s requirements, and since then, ATF has relaxed somewhat on the idea of M16 parts in AR-15s.
In more recent years, bolt carriers tend to be one of three designs:
Three common types of AR bolt carriers, from top to bottom: (1) SP1 type semi bolt carrier group; (2) partially cut-down semi bolt carrier group; (3) M16 style full-auto bolt carrier group.
The creation of collar lock was only necessary in the light of over-fulfilling the ATF requirement to make ARs hard to convert to full-auto; since ATF has ruled that M16 bolt carrier group parts in a semi AR are not ipso facto a machine gun in the absence of any M16 or unmodified fire control group parts, for most builders the best answer for reliability is to use an M16 style fire control group (#1 in the image above). A full collar, semi group like #2 is also good. It has the region of the carrier which trips the auto sear removed, but retains the firing pin shroud. If you must use a Colt or other carrier like #3, be mindful of firing pin collar size and the fact that most aftermarket pins will not function properly without modification. (It’s a decent “beginner’s first lathe job” to turn a firing pin collar down, but the material is stainless steel and tough to cut).
So what can go wrong if you mismatch parts with an open, unshrouded bolt carrier? As we said above, “collar lock if the disconnector fails is a good thing, because it prevents a runaway gun; collar lock without disconnector failure is pathological.” And collar lock is an extreme example of something going wrong, and you’re very unlikely to see it. (We’ve only seen one instance in the wild, and we’ve watched literally millions of M16, M4 and AR rounds go downrange). What’s more likely is wear to your gun. A definite sign of collar size mismatch in an unshrouded-carrier gun is a bent firing pin retaining pin. This is the small shaped-wire pin (often called a “cotter pin,” which is not correct terminology) that holds the firing pin; it’s the first thing out and last in when you disassemble the bolt.
The early AR-10s and earliest AR-15s (pre-M16) had a machined steel pin in this position, satin chromed like the rest of the BCG. Changing to a vastly easier-to-make wire pin was smart from a manufacturing standpoint; this part is normally very lightly stressed. If it’s getting beat up, something’s wrong in your system, and Occam’s Razor points us to the firing pin collar.
In high-round-count guns, the firing pin itself can get all beat up and scarred. In the original AR design, the bolt carrier pushes the hammer down until the disconnector grips it (or trigger grips it, if the trigger is already reset, which is unlikely in normal firing); in the SP1 design, the firing pin can contact the hammer. The FP is harder than the bearing surface of the hammer, but not by all that much; both surfaces get wear and the firing pins look beat up.
Finally, this design, wherein the BC was modified, is a credible response to a designer’s very real concern (to fail-safe the disconnector and prevent a runaway gun). Even today, some reputable manufacturers ship guns with this form of BCG; Colt persisted in doing it through the HBAR era (our only recent Colt is a Colt Defense LE SBR and has a mil-spec bolt carrier, so we can’t describe their current civilian market product), and Ruger’s SR556 and newly-announced SR762 piston ARs have unshrouded bolt carriers, and they work perfectly fine and hold up well. You just need to be aware of the technology before you go swapping parts.
The extensive modularity of the AR series, which led Colt to the before-its-time CAR family of weapons and now supports a multi-billion-dollar worldwide industry, is not universal. This is because of modifications like this that subsequent parts makers didn’t know about or understand. It’s also because there’s now such a wide variation in ARs and parts out there that even the most conscientious quality-control manager can’t anticipate every combination, or even what the end conditions are.
For 30 years in the Army, we were blissfully unaware that such a thing as an unshrouded bolt carrier existed. When one first showed up in the parts pile, our response was probably unprintable, and in our ignorance we attributed it to the work of Bubba the Gunsmith™. But we looked into it and discovered the logic behind it that made reputable firms like Ruger and Colt adopt this as a safety measure in their semi ARs. For the average shooter, this will never be a concern. It’s more of the problem for the guy who builds his ARs out of parts or who buys ARs built by manufacturers who are mere assemblers without the engineering or gunsmithing depth to address any problems. And even if you have problems, the good news is that the AR’s very modularity makes it typical AR problem: one that gives you several pathways to a fix, and a reliable AR.
Just how accurate is a .50 caliber rifle? The Fifty Caliber Shooters Association can tell you. The world record, set in 2009 by Lee Rasmussen, is a 5-shot group of 1.955″. Before you say “better than 2 MOA, that’s not bad,” that’s not a 100-yard group. That’s a thousand yard group! It works out, they tell us, to 0.1868 MOA. (Note:this is disputed in the comments, where Greg who did the math comes up with 0.1867 — a difference of one ten-thousandth of a minute of angle, perhaps, but math is math and correct is correct – Eds).
(The only .50 we’ve shot, a pre-M107 Barret M82A1, was a 2 MOA gun with match ammo, which we usually didn’t have. It was minute-of-general-neighborhood with ball ammo).
By the way, it wasn’t just any day that Rasmussen broke the 10-year-old record: it was the 4th of July.
We’ll let the FCSA tell their own story:
The Fifty Caliber Shooters Assn., Inc. (FCSA) was established in 1985 by a small group of dedicated people who set for themselves the mission to advance the sporting uses of the .50 BMG cartridge. The FCSA is a non-profit organization registered in Tennessee and Utah .
FCSA provides a quarterly magazine, VERY HIGH POWER™, a Suppliers Directory, professional consulting information on fifty caliber rifles, and reloading information for its membership. In addition FCSA maintains an active, comprehensive web page at www.fcsa.org offering accessibility and insight into the organization for internet visitors and members alike..
Our primary sport at this time is 1000 yard shooting competition with a mission to advance the art of extreme long-range accuracy with the fifty caliber rifle. FCSA sanctions approximately ten to fifteen organized 1000 yard rifle matches per year in various locations in the continental United States.
FCSA has over 4000 members and is growing steadily. FCSA has members in twenty-two countries including England , Switzerland , Finland , South Africa , Australia & Canada .
The organization also believes, with some justification, that it is civilian large-caliber shooters who lead the way, and the military long-range sniper program trails. There is some justification for that belief.
The FCSA provides a service to military and law enforcement with research and instruction as well as an active liaison in both communities. Major John Plaster, USAR (ret) has written in his book ULTIMATE SNIPER, “most of today s .50 caliber military sniper rifles were developed without one single dollar of govrtnmrnt money.” To give credit where credit is due, it has been the private sector perfectionist of the Fifty Caliber Shooters Assn. who has lead the way in refining .50 caliber cartridges, rifles and 1000 yard plus shooting know how.
The site is interesting and it and its links worth exploring not just for big-bore buffs, but for anyone intrested in accurate shooting.
There is even a kindred organization in the UK for British large calibre gunners — God love them. And there’s also a version in der Schweiz;the Swiss FCSA is available in all four actual Swiss languages: English, French, German and Italian. (That’s a joke, for any humourless Romansch speakers out there). So for once we have a crumb to throw to some of our international readers, to whom we seldom, in our USian isolationism, have links we can serve.
One interesting factoid about the Swiss .50 shooters — on some ranges, silencers are mandatory. Is there any place on Earth more civilized that Switzerland?
This would fit in a Cobra cockpit… if only the pilots could get them.
In 1969, AH-1 Cobra crewmen flying over Vietnam wanted CAR-15s for self-defense if they had to set down in Indian Territory. This is the story of how they asked, and how the Army said … no, leaving any such unhorsed knights of the air to face the NVA (by 1969 VC were no longer a factor) with nothing but a .45 or a .38 revolver.
Big Green did not much care for the XM177, and by the summer of 1969, it was on its way out, so even if higher echelons sympathized with the pilots’ need, they might have been unable to help very much.
Every takeoff gets a landing, but the pilots don’t always get to pick where they land. (The crew whose 1972 predicament is shown in this artist’s rendering survived, believe it or not).
The tale is told in a once-classified document. On 11 Aug 69, as part of a periodic report, an aviation unit in combat in Vietnam, the 268th Aviation Battalion, requested “CAR-15s” as defensive weapons for AH-1G HueyCobra crewmen.
It seemed like a logical request. If forced down, unlike UH-1B/D “slick” helicopter crews, Cobra gunship pilots couldn’t rely on their door gunners’ M60Ds, and again unlike slick crews, they couldn’t stow a personal M16A1 aboard their skinny copters:
Observation: Army aviators flying AH-1G aircraft in RVN require a defensive weapon.
The office is as big as it needs to be, but there’s nowhere to stash an M16.
Evaluation: Experience indicates that Army aviators flying the AH-IG require a defensive weapon in addition to the standard issue ,38 cal. revolver. The M-16A1 cannot be carried in the cockpit because of its length. Due to its compact size and proven efficiency, the CAR 15 could fulfil this requirement- This additional weapon is particularly needed because of the diminished crew of the AH-1G.
Recommendation: Each pilot flying the AH-IG be issued CAR 15 as a defensive weapon.
Command Action: The suggesting unit has submitted an MTO&E incorporating this change.
It sounds logical, and the 17th Aviation Group, the next highest level of command, was in agreement by 15 Sep 69:
Paragraph 2e, Logistics, Page 6: Concur. These weapons
were previously requested by another unit utilizing AH-1G helicopters.
The USARV G4 Section stated that the CAR-15 was an ENSURE item, has been adopted as a standard item of equipment, and a POI has been developed. The USARV G4 Section further advised that the wearon is not in production bucause of increased emphasis on production of the M-16 rifle. Command action is deemed appropriate.
By 27 Sep 69 the 1st Aviation Brigade, the grand pooh-bah of Army aviation in Vietnam, agreed:
This headquarters has reviewed subject report and concurs with th:e contents as indorsed….
But a higher command finally got around to saying “nay”. US Army, Vietnam, was the big HQ with the big picture, and by 1969, the CAR-15 was not in their picture at all. On 13 October 1969, a document signed by an Adjutant Generals Corps lieutenant rained on the aviators’ parade:
Reference item concerning “Logistics,” section II, page 6 paragraph 2e; nonconcur. No additional quantities of the XMI77 SMG (CAR-15) will be procured. Units currently authorized the XM177 SMG in MTOE and TDA documents will change LIN Z76282 (XM177) to LIN R94977 (M16A1). The XM177 SMG will be supported through cannibalization when on-hand spare parts are exhausted.
The pilots had to make do with pistol or revolver, period. Sorry about that.
1960s term for an AR-15 carbine
Colt tried developing the AR-15/M16 into a series of weapons called the Colt Assault Rifle -15 (CAR-15) family. Except for the short carbine, which the Army called a submachine gun, none of the variants really took off and most of them exist only as toolroom prototypes. “CAR-15″ became service slang for the weapon officially known to the Army as various marks of XM177 and to the Air Force as the GAU-5.
Army logistics program
The ENSURE project encompassed procedures for Expediting Nonstandard Urgent Requirements for Equipment and was initiated on 3 January 1966. The purpose was to provide a system to satisfy operational requirements for nonstandard or developmental matériel in a responsive manner and bypass the standard developmental and acquisition procedures.
A Logistics or supply office in a smaller command is S4; one in a joint command is a J4. G/S/J 1, 2, and 3 are Personnel, Intelligence, and Operations, and these are historically the four principal staff sections.
A LIN is used by the Army to identify end items of equipment in logistics records and databases, including MTOE/TDA. An LIN may or may not map directly to a Federal, National, or NATO Stock Number. Other services may have their own equivalent numbering systems for the same end item.
American acronym for the bad guys’ army. Officially it was the PAVN: People’s Army of Viet Nam.
Program of Instruction
This is fundamentally a series of lesson plans covering a subject. A POI for a weapon (like the XM177E2) would describe how to train users to employ and maintain the weapon, and would include both classroom and firing-range lessons.
This was the highest level of support command in Vietnam 1965-72. The highest operational command was MACV (Military Assistance Command, Vietnam) which merged with USARV in 1972; all US forces in Vietnam disbanded in 1973.
“Vietnamese Communists” in Vietnamese, it was the American acronym for communist guerillas in the South. The VC were so badly beaten up during the Tet Offensive in Jan/Feb 68 that they were eliminated as a factor in the war, at least militarily.