Category Archives: Machine Guns

A Tale of Two Temperatures

Consider this graphic. It is a somewhat crude reproduction of one in the Rheinmetall weapons design handbook. Secretary of State John F. Kerry, who is unlucky at bicycles bur uncannily lucky with heiresses, thinks that we all should be criminals for discussing this online, so let’s all get our crime on and return to a subject we’ve discussed before, heat management  in automatic firearms.

temperature_over_time_mg_barrel

 

The original of this graphic is a rather dull monochrome one in the style of the rather dull, unless you are the sort of gun geek that Secretary Kerry dreams of decanting into durance vile, Rheinmetall Handbook. Our copy is the German language version, because we read po-nyemetskiy, and Amazon.com wants $300-400 for an English copy, when there is one to be had, but Amazon.de has copies of this out of print classic for about €100. (Which is going to be lunch money if they keep letting Greece set continental fiscal policy). It took us several iterations to get the slopes about right, and we got the round-count wrong: it’s supposed to be two neat Teutonic bursts of 10, and we have a rather limited and non-Aryan 8 and 9, but with that difference noted, this graphic is  close enough to discuss the phenomena at issue. Here’s what Rheinmetall says about this graphic:

The barrel of an automatic weapon is, as a consequence of the normally high rate of fire, subject to extraordinary temperature demands.

[This illustration] shows the approximate course of temperature of the inner- and outer wall of an MG barrel in two bursts of fire of 10 shots each with a pause lying in between. Feel long, or many short, bursts of fire can drive the temperature of the inner wall so high, that it has a significant influence on the material toughness and therefore on its use and employment.

In this, the cadence of fire, the number of shots in a burst, the pauses, the lengths of the pauses, and the number of bursts of fire fired rapidly one after the other, in conjunction with the thermal resistance of the barrel material and the strength of the barrel walls all play a role.

Comparable barrel-life shot counts can therefore be reached with the same firing rhythm. Often the “French anti-aircraft rhythm” is used: this is 144 shots in 12 bursts of 12 shots each, with a 2-second pause after each burst and a 20 second pause after every four [bursts]. With MG barrels, a firing rhythm of 250 rounds in numerous bursts is often used.

For testing automatic weapons and their ammunition, Rheinmetall has developed an electronic Rate and Rhythm Control Apparatus, which is described below in section 7.7 [of this book].

Measures for increasing the life expectancy of barrels include:

  • Heat-resistant materials;
  • Chroming or Nitriding the interior wall;
  • Progressive twist and rifling profile in conjunction with barrel caliber tightening.

Less effective are cooling fins and water cooling.

Barrels for MGs and machine cannon must be rapidly interchangeable.

Now, this graphic is limited in its utility because in its original version, it comes without any numbers attached (accordingly, we have eliminated from the version we show you, the numbers we used for temperature (ºC; as you might expect the Handbook exclusively uses SI units) and seconds to approximate the original. But we can draw some conclusions based on the shape and gradient of the two lines.

Our take-away is that the key point is that the baseline is higher after each burst, and that the internal temps go higher in each successive round of each successive burst. What does not show on this line is the temperature where the barrel fails. As we have seen in the M4 experiments wherein a carbine was tested to destruction, this happens at a fairly predictable and repeatable, ergo constant from an engineering point of view, temperature. As Rheinmetall points out, several roads will get you to that temperature sooner or later.

Maybe he didn’t know this, but thus is why your sergeant whacked you upside the hemmet and told you to fire shorter bursts.

Looking at the Rheinmetall data, it seems that for their test weapon, whatever it was (MG3?), the barrel recovers its temperature rather speedily after the passage of each bullet momentarily superheats it. We would attribute this to the limited ability of a small projectile’s friction to heat the much greater mass of the barrel — this is also why the internal and external temps diverge so widely. But note that the internal temp continues to ride steadily as long as a steady sequence of pause and fire is applied, and at each pause the internal and external barrel temps have diverged more widely.

The implication is that an automatic weapons barrel is going to be heated to its limits at some point, moreover, at some predictable point, in any continuous fire regime, and while some of the magic designers have used over the last century, like chrome plating and stellite liners, can give you some more rate of fire on the margins, only changing out the barrel (not usually possible in a light automatic carbine) or otherwise giving the barrel a chance to rest and recover from high temps will prevent failure.

Thus endeth the lesson. Apart from further education which may come in the comments.

 

Did The US Adopt the FG42 After All.. as the M4?

“Hognose,” you are thinking, “has lost his ever-lovin’ mind.” Unless you were long in the service, in which case you will substitute a stronger term for “ever-lovin’.” Because, after all, the low-production FG42, which had a great influence on US postwar weapons development, is miles from today’s modular M4, which developed from a completely different concept, the SCHV (Small Caliber High Velocity round) and the selective-fire assault rifle.

FG42-Right

m4a1_sopmod_rails_system_left_clear

Let’s go back to one of the earliest versions of the US reaction to captured FG42s, written by T/5 (a wartime grade for technical specialists, called “technical corporal” and paid a hair better than a “mere” corporal) John E. Holmes of the Foreign Material Branch at Aberdeen Proving Ground on 8 June 44. According to Dugelby & Stevens, this was “the first American appreciation of the FG42 to appear in print… therefore a most noteworthy document.” After describing the general arrangement, production characteristics, handling and originality vs. derivation of various FG42 features (the example(s) Holmes had was/were the “E” type or first model FG with the stamped metal butt and pistol grip), he suggests that its advantages might be well considered in future US martial-arms design:

Advantages of Design

The combination of advantageous features included in the design of this weapon has made it a very interesting piece which should be studied with future weapons in view.

The following features are suggested:

a. The method of reducing required by using buffer spring sliding shoulder stock system.

b. Reduction of muzzle climb due to the action and stock design.

c. The method of loading empty or partially empty magazines with standard rifle clips, cutting down the number of necessary magazines which must be carried.

d. High line of sight prevents distortion of target due to heat waves.

e. Folding sights prevent damage as the weapon is carried by paratroopers, or when not in use.

f. Reversible bayonet.

g. Telescopic bayonet.1

Do you see what we mean? The only ones of these that are not present in the modern infantryman’s M4 are the spring-loaded shoulder stock (not necessary on the light-recoiling 5.56mm cartridge, perhaps), and the “reversible” spike bayonet. In point of fact, the US already tried that with rod bayonets on the Springfield rifles of 1880-1888 and 1903, which were extremely unpopular with troops (and ultimately, overthrown by President Theodore Roosevelt as “as poor an invention as I ever saw,” leading to the familiar M1905 knife bayonet of the World Wars).

So no, we never adopted the FG42. But over the years, we did adopt most of its impressive features. So did almost every major military in the world. And that is why the FG42,  despite having been produced in a quantity of only 8,494, maximum2, is, legitimately, considered one of the most influential weapons in history.

Notes

  1. Dugelby, Thomas B, and Stevens, R. Blake. Death From Above: The German FG42 Paratroop Rifle. New Expanded Edition. Coburg, Ontario: Collector Grade Publications, 2007. pp. 119-120.
  2. Ibid., p. 121.

MGs in the Russo-Japanese War

And, given the established subject of this blog, you know that our reference is to machine guns, not to the products of Morris Garages.

The Russo-Japanese war was the first war to introduce all the nightmares of 20th-century warfare: barbed wire entanglements, recoil-carriage artillery, and of course Mr. Maxim’s new invention, the machine gun. Apart from the MG, all of these had seen some use before. But the Russo-Japanese war fully foreshadowed the Great War to come.

Japanese MG position

Japan shares with Russia the dubious distinction of having fought the first major war of the 20th century, and the first in which machine-guns on both sides played a prominent part in significant numbers. Maxim Nordenfelt and later VSM1 supplied both protagonists – the Japanese bought four 8mm Maxims in 1893, and later nine ” New Pattern” Model 1901s; the Russian Navy bought almost 300 guns of various types between 1897 and 1904, while the Russian Army obtained perhaps as many as 1000 guns from Loewe/DWM between 1899 and 1904. Later, the Japanese switched their allegiance to the Hotchkiss, and the Mle’00 was the gun which armed most front-line units of the Japanese Army by the time of the outbreak of war with Russia.

Initially, both sides deployed their machine-guns like miniature artillery, laying down indirect fire from rear positions, over the heads of their own infantry; observers (and, just as during the American Civil War, there were many) reported that the Maxims, in particular (they were chambered for a heavier around than the Japanese Hotchkisses) were actually more effective in this role than the artillery they mimicked.

Shades of things to come; the same tactics were to be used on the Western Front during the First World War, but not at first.

More important than the role of supporting attacking infantry, though, was the machine-gun in static defence. In an engagement dear Lin Chin Pu, in January, 1905, a German observer reported:

The Japanese attacked a Russian redoubt defended by two Maxim guns. A Japanese company about 200 strong was thrown forward in skirmishing order [that is, in rough liner breast, with some space between each man]. The Russians held their fire until the range was only 300 yards and then the two machine-guns were brought into action. In less than two minutes they fired about a thousand rounds, and the Japanese firing line was literally swept away.

The propaganda of the war was one thing, the reality different (as always).

The propaganda of the war was one thing, the reality different (as always).

At the battle of Mukden, which began on 21 February 1905, when the Japanese attacked Russian positions over a wide front, and proceeded to encircle them, the Russians employed their Maxims in batteries of eight, with one gun undergoing overhaul for each battery in action – the defenders were expending machine gun ammunition at the height of the battle at a rate of over 200,000 rounds per day. The Japanese encirclement was completed (notwithstanding the fact that the Russians had withdrawn by then) on 10 March by which time the defenders had lost an estimated 90,000 men killed, to the attackers’ 50,000; as many as half the casualties have been attributed to machine-gun fire.

As the war in Manchuria played itself out, it became exceedingly clear to participants and observers alike that the machine-gun had come of age with a vengeance. The British observer, Sir Ian Hamilton, writing in his Staff Officer’s Scrapbook of The Russo-Japanese War, described an incident which took place the following October, after six Japanese Hotchkiss guns have been allowed to occupy high ground overlooking the Russian lines:

In less than one minute hundreds [of Russians, who were complacently eating their lunch] were killed, and the rest were flying eastwards in wild disorder. Next moment the machine-guns were switched onto the Russian firing line who, with their backs to the river and their attention concentrated on Penchiho, were fighting in trenches about half-way up the slope of the mountain. These, before they could realize what had happened, found themselves being pelted with bullets from the rear. No troops could stand such treatment for long, and in less than no time the two Brigades which had formed the extreme left were in full retreat. Altogether the six machine guns had accounted for… 1,300 Russians.

Despite Hamilton’s warnings, the British Army establishment still took little heed of the danger posed by the machine-gun; not so the German, even if the conclusions of one of its observers in Manchuria proved to be faulty:

Machine-guns are extraordinarily successful. In defence of entrenchments especially they had a most telling effect on the assailants at the moment of the assault.

But they were also of service to the attack, being extremely useful in sweeping the crest of the defenders’ parapets. As a few men can advance under cover with these weapons during an engagement, it is possible to bring them up without much loss to a decisive point.

The fire of six machine guns is equal to that of a battalion (of riflemen) and this is of enormous importance at the decisive moment and place.

Whichever of the two opponents has at his disposal the larger number of machine-guns has thereby at his command such a superiority of fire that he’s able to give an effective support to his infantry. He can occupy a considerable front with smaller groups – and economy of manpower. Infantry is thus more free to maneuver and becomes more mobile. (Emphasis Ford’s).

Both sides used their machine-guns to enfilade dead ground, and thus deny it to the enemy, with considerable success, but the Japanese went one better when they pioneered the use of indirect overhead fire to support infantry assaults. On 13 March 1905 Japanese infantry crossed a river and assaulted enemy defensive positions on the other side with comparative impunity thanks to a covering barrage from machine-guns sited 1,800m (2,000 yards) in the rear, which kept firing until the assault troops were within 40 m of the Russian trench line.2

We note that modern armies train little for that kind of MG support, but the World War I and inter-war armies trained these tasks obsessively.

Both Japan and Russia came out of the war committed to machine guns.

Notes

  1. Vickers, Son & Maxim, the successor to Maxim Nordenfelt and the forerunner of the Vickers defense industrial combine.
  2. This entire long excerpt comes from pp. 81-84 of Ford, Roger. The Grim Reaper: Machine-Guns and Machine-Gunners in Action. New York: Sarpedon, 1996.

An MP5 Shot for How Many Rounds? 571,000. Seriously.

Most service-weapon users (meaning, the organizations, more than the men) do a really lousy job of tracking how many rounds go through their weapons. This results in things like some of the crappy-shooting old rifles units have in their arms rooms, and also in a lot of money wasted overhauling guns that aren’t really due for it yet (because maintenance is done “on schedule”), or spending a fortune on periodic inspections (so that maintenance can be done “on condition”). The average line-unit armorer is a supply clerk, trained to rack and un-rack rifles and maintain accountability; he lacks the training and inspectional technology to determine when any firearm needs to be overhauled, absent a truly egregious problem.

MP5 SBR2

File photo of an MP5A3 (actually, an SBR).

And while the Army wants guns to count their own rounds, we’re not there yet. (And they haven’t yet considered the CI implications of round counters on rifles).

KSC_SWAT-LogoBut the security force at Kennedy Space Center in the 1980s did count rounds through their training weapons, and so they set, as far as anybody knows, the record for the World’s Most Used MP5. The story is told in Frank W. James’s 1996 book, Project 64: The MP5 Submachine Gun Story. (Now, unfortunately, out of print and rather pricey on the secondary market; his 2003 book on the MP5 may or may not have the same content, but it’s out of print, too). 

Depending on training demand, Serial Number 316019 fired from 3,000 to 15,000 rounds a month, every month, in its five-and-a-half-year service life, from August, 1984, to January 1990. Peak year was 1988, with a staggering 128,000 rounds going downrange from the HK subgun.

It didn’t make it all the way to its end count of 571,600 rounds with all the original parts, but it did have the original barrel — grossly out of spec, it’s true — and most major parts. The parts that failed are ones that will be familiar to anyone who’s run MP5s, and were all replaced at end-unit armorer level: firing pins and springs, extractors and springs, rollers, roller holders and pins, and various other springs, plus some parts physically damaged in training, like a handguard and a retractible (A3) stock. Some parts, like extractor springs, for example, have a wear-out schedule or recommended replacement point in HK maintenance documents, but KSC ran the guns “on condition” and went far beyond the recommended intervals before replacing these parts.

It was still working, after a fashion, in 1990, but had lost all accuracy and had headspace issues (both are probable results of the worn barrel). HK would have refurbished the gun, but it would have cost nearly as much as buying a new one, so the facility bought new guns instead.

The gun does not appear to have been fired after January 1990, but it was formally withdrawn from service in 1992.

It would be nice to say that the gun wound up going back to Oberndorf for engineers to study, or wound up in a museum in light of its very high round-count, but in fact it wound up initially being cannibalized to keep the Center’s other old MP5s running, and then being destroyed.

It was only a machine, but some of us are sentimental about our machines. We will always believe that it deserved a better end.

How Many Rounds Does an MP5 Magazine Hold?

Is this a trick question? “Ah, tricksy is he, the Weaponsman. He’s tricksy!”

H&K's most common MP5 variant, the MP5A3.

H&K’s most common MP5 variant, the MP5A3.

Well, not really. Maybe it’s the Teutons of Oberndorf who are tricksy. But there might be more going on here than you think. Answer and explanation after the jump.

How many rounds does the factory 9mm MP5 mag hold?

pollcode.com free polls

Continue reading

Sometimes the Law is Not an Ass: Type 99 Escapes Torch

This is a remarkable story of how a Marine’s war trophy went from seized contraband to museum display — thanks to a change of heart by members of an ATF field office.

[A] World War II relic, which spent nearly 35 years under lock and key in the LaSalle County Sheriff’s Office, has traveled its own unique path through time and has now finally made it to the Livingston County War Museum in Pontiac.

sullivans japanese Type 99

The item in question is a Japanese Type 99 light machine gun, recovered by U.S. Marine John Sullivan in the heat of battle. His daughter, Jane Sullivan-DePaoli, who was on site at the museum for the recovered artifact’s presentation, recalled the incredible events surrounding his capture of the gun from enemy forces in the Battle of Iwo Jima.

“All the men were lined up, taking fire from a pillbox,” she said, recalling her father’s story, “My dad went in the pillbox, and the gunner turned on him, but he was able to take him and his assistant out.

“After the battle, he went back and the machine gun was still there, so he took it.”

via War Museum welcomes unique weapon loan – News – Pontiac Daily Leader – Pontiac, IL – Pontiac, IL.

At the time, firearms as war trophies were not against US law, but the USMC had restrictions in place, so Sullivan and two of his buddies each took a piece of the gun home as “shrapnel.” Nobody looked too closely, and Stateside, he was able to reassemble the gun. It hung for years on the wall of his home bar — and then some non-friend of his dropped a dime to the ATF.

john_sullivan_usmcYou see, he could have registered the gun — until 1968, when the Gun Control Act clamped down on registrations of guns that had missed registration. The law directed ATF to hold an amnesty then, and thereafter more, periodic amnesties… but after the first one, the agency, whose senior leadership had come to see itself at war with the 2nd Amendment and gun owners, never held another.

The tip came in 1981, and while the ATF had its share of bullet-headed attack bots then, it was nothing like the agency of today. A Special Agent was dispatched to link up with local deputies and talk to Sullivan. They quickly decided that, even though the gun was technically contraband under Federal and Michigan law, they weren’t going to arrest the Marine hero. One of the deputies, now LaSalle County Sheriff Tom Templeton, remembers:

We talked for awhile, and John told the ATF officer and I how he got it, and recovered it from the beachhead. He said, “Do you know how many Marines were killed with that gun?” And he said “I’m the one who silenced it, I brought it back, and its mine.”

But there was that small problem of the law — the gun was illegal, and there was (and is) no way to make it legal, short of destroying it. So they took it and locked it up at the Sheriff’s Office for the next 30 years, while periodically arguing about whether to destroy it.

At the same time, the Special Agent, whose name is apparently lost to time, must have realized that, while the law made possession of this gun technically criminal, it had zero value as a crime weapon, and great historic significance. So did Templeton, whose father was a WWII veteran, and who is a veteran himself.

Recently, Templeton, the Detroit Field Office of the ATF, and Sullivan’s daughter managed to negotiate terms that brought the elderly gun to a secure glass case in the museum.

Meanwhile, the ATF had been close to approving an amnesty especially for war trophy weapons in the late oughts, until the advent of management that prioritized lobbying for new anti-gun laws, and building a case for them by arming Mexican narcotraficantes. 

But even in that environment, they managed to save Sullivan’s historically significant trophy from the torch, and put it on public display: because the guys and gals out in the Field Offices are not clones of the badge-wearing politicians at HQ.

Sometimes the law is not an ass.

Canadian Machine Gun Resto Project

Two machine guns in battered condition on a Canadian war memorial are being examined and will be cosmetically restored to their original condition — and efforts are underway to determine their true provenance and history.

Both are German MG08 guns. The one in this picture, on the south side of a roadside cenotaph in Harold, Ontario, was captured in 1918 at Arras; the hole in its water jacket may have been caused by Canadian fire. The cenotaph itself is rare: most Canadian cenotaphs list only the war dead, but this lists the returned surviving veterans as well as the fallen.

MG08, captured at Arras, 1918.

A pair of 100-year-old German guns, taken as souvenirs at the end of World War I, will be temporarily removed from the cenotaph on Highway 14 to be refurbished thanks to the efforts of the local branch of the Royal Canadian Legion and the Stirling-Rawdon Historical Society.

Silenced in 1918, the guns will never fire again says society member John Lowry, but they will be cleaned up and returned to their original colours, perhaps even solving a few mysteries along the way. Lowry explains that significant research has been done on the weapons, a pair of Maschinengewehr 08 machine guns captured by 2nd Division CEF troops at the end of the war, but there are many unanswered questions as well.

via Machine gun restoration project under way.

John Lowry and Phil Martin of the Historical Society will try to match the gun’s original color scheme — if they can determine what it is — and answer the question of what made the hole in the Arras gun. They’re also trying to find photographic evidence tying the gun’s partner to a particular location or battle.

John Lowry (l.) and Phil Martin (r.)

Lowry thinks the hole in the water jacket may have been the act of a Canadian sniper:

[T]he Arras weapon appears to have been disabled by a sniper’s shot and the restoration may lead to a conclusive answer, he adds, “if we find a .303 bullet in there.” Lowry says that the guns, capable of firing 500 rounds per minute, were water-cooled using a chamber that surrounded the barrel and marksmen would deliberately aim for it hoping to quickly overheat the weapon rendering it useless.

According to the article, trophies like this were once commonplace across Canada, but the herd — once numbering some 15,000 captured arms, originally intended to populate a grand war museum, but on the project’s cancellation scrapped or spread across the very large country — has been thinned, less by time than by WWII scrap drives.

[T]he remaining local pieces, which also include a trench mortar in Madoc and a field artillery piece in Trenton, are only a small fraction of the enemy weapons that ultimately arrived in Canada after World War I. …. A significant number, Lowry says, were scrapped during World War II, including a pair of machine guns received by the village of Stirling. The fate of a similar pair that arrived in Marmora is unknown, but they too may have been scrapped.

The Stirling Branch of the Royal Canadian Legion has raised the cost of the MG restoration. And no, they won’t be restored to firing condition — it is Canada up there, which is kind of like Massachusetts with more polite people and much better drivers.

Before there was “Reverse,” it was just “Engineering.”

So, let’s take a look back at something we’ve been discussing recently: reverse engineering. The term is a relatively new one, but the practice is older than engineering itself. When you get right down to it it’s just “copying.” And manufacturers have been doing that since… Well, since sometime very soon after they first started manufacturing!

Sometimes the drawings (here a Swedish BAR from gotavapen.se) come after the engineering.

Sometimes the drawings (here a Swedish BAR from gotavapen.se) come after the engineering.

Bear in mind that parts were not made from drawings until well into the 20th century. Specific jigs and measuring tools were made to ensure that parts were produced in conformance with a physical, mechanical prototype. And designers didn’t work from, or produce, drawings, at least not exclusively: a designer like John M. Browning produced a physical, working model, and brought that to his manufacturing partners. They engineered it for production. Sure, he made drawings, or had them made, but that was for patent purposes (below, right).

bar_patent_hqIn the early twentieth century, talent in gun design usually resided in a different man than talent in production engineering. (There were some who could do both, like John Garand and some of the Russian masters, like Vladimir Grigoryevich Fyodorov, but they were rare).

So in John Browning’s day, putting any of his guns into production was, to one extent or another, an exercise in what we would today call reverse engineering. Production engineers would review the prototype, gain an understanding of its design philosophy and features from the designer, and then figure out how to mass-produce the weapons. And the World War I Browning Automatic Rifle may be the greatest reverse engineering saga you haven’t heard.

Winchester, the firm, was struggling when it was tasked to produce Browning’s new designs, the Browning Automatic Rifle and the yet-nameless .50 caliber machine gun, with priority to the auto rifle. There was only one problem: there was only one prototype or specimen BAR in the world, and Colt had it, and was re-engineering it all day long, Monday to Friday. In the spirit of wartime cooperation, Colt would let its New Haven rivals borrow the new firearm – for a weekend.

Winchester 1918 BAR

Winchester, which had seen massive orders, but incurred staggering debt in order to fulfill them, needed the order badly. They accepted what seemed to be an unreasonable offer.

In September 1917, Winchester was instructed to commence tooling up for the manufacture of the Browning Automatic Rifle (BAR). Edwin Pugsley, then Manufacturing engineer, went to the coat factory to see the only existing model. Since the BAR was needed at Colt during the work week, it was borrowed for a weekend, and in that time drawings were made and the project begun. By the end of December The first Winchester BAR had been completed. Production was well on by March, and by Armistice Day, November 11, 1918, Winchester had made approximately 47,000.

Winchester also had begun construction of the Browning .50-caliber machine gun and had a working model completed within about two months. That gun, however, never entered into production, because of the end of hostilities.1

The earnings from wartime contracts, including 1917 Enfield rifles, riot guns, and the BAR, were substantial: $76 million. It wasn’t enough to retire all of Winchester’s debt, a substantial $16 million, but they were able to pay off about half of it. The company still had to reorganize and the Winchester-Bennett family wound up giving up control.

Winchester 1918 for sale by Craig Gottlieb. It has some M1918A2 parts (stocks & trigger guard with mag "ears").

Winchester 1918, once for sale (no longer) by Craig Gottlieb. It has some M1918A2 parts (stocks, flash hider, & trigger guard with mag “ears”). More images of the same gun at the link (all the M1918 photos in this post are of that firearm).

But it’s hard to beat, in the annals of reverse engineering, the one-weekend crash metrology and documentation Winchester had with the world’s only BAR before delivering it back to the Colt engineers in Hartford, and that produced the wartime BARs and led to the rifle’s future as the basis of fire in the American rifle squad, not in time for that war but in plenty of time for the next two. This is especially remarkable when you consider the sheer complexity of the BAR. It has scores and scores of parts.2 (Winchester cheated a little, for example, by using the sight they were already producing for the M1917 Enfield rifle).

winchester_1918_bar_left_crop

The problem, of course, with two independent reverse-engineering projects? Parts from the Colt Monitor don’t interchange 100% with Winchester’s military BARs. But what do you want for two days?

Update 1000R 8 Apr 15

This post has been corrected. Several (more like twenty) unproofread dictation failures have been fixed. We’re not sure we got them all. Thanks to Ullr in the comments.

“I don’t need to check it… it was done last night, just needed the pictures.” Zug.

Notes

  1. Wilson, RL. Winchester: An American Legend. New York, 2004: Chartwell Books. p. 171.
  2. As well Hognose knows. He was sure he was going to flunk BAR in SF Light Weapons School in 1983. “Cups and cones, cups and cones….” He pulled out a pass on the BAR, but got a downcheck on the M3A1 Grease Gun, of all things (IIRC you could get two downchecks, or maybe it was three. Didn’t want to test the limits).

 

 

Transferable History

We’ve featured an MP.18-II before, which is a later iteration of this exact same gun, with a magazine well reconfigured for straight magazines. (It led in turn to the MP.28, the Lanchester, and the Sten, by fairly direct process of derivation). But this gun, the MP.18-I, is the granddaddy of them all, and it could be yours.

MP.18-I 03It is certainly the first widely produced submachine gun, defined as a shoulder-fired infantry weapon firing a pistol cartridge with an automatic or select-fire mechanism. A blowback mechanism, it showed the way for many designs that would follow through three generations of submachine guns, until the rise of compact versions of intermediate-cartridge assault weapons would replace most of them.

Some would say it has a face only a mother could love:

MP.18-I 28

 

And it’s just as awkward looking from behind. MP.18-I 24

The drum magazine is so odd looking because it was already in production for the Lange P.08, the “Artillery” Luger. Rather than try to design a thirtyish-round magazine, the engineers at Theodor Bergmann in the weapons-manufacturing center Suhl, Germany, did what many later gun designers would do and borrowed a proven one.

MP.18-I Snail Drum 03

 

The gadget with the lever is the magazine loader, a must-have for these unique mags. Note the sleeve that fits on them for SMG use.

MP.18-I 06

Like all first-generation submachine guns the MP.18-I is made using the rifle processes of the early 20th Century. It is primarily made of steel parts machined from billet or forgings, richly blued; and the stock is solid walnut. If four years of relentless naval blockade had damaged the German Empire’s war production capabilities, this gun doesn’t show it.

The auction has a very reasonable opening bid, for what it is, but there is also a reserve. No, we don’t know what the reserve is.

As the catchy song goes, what does the ad say?

This is a really nice example of the early 9 mm German submachine gun used in WWI. MP18-1 was the first true Submachine Gun. This is not all matching, but is an excellent example with an excellent bore.

These are very rare and hard to find because most MP18’s were modified to accept the straight magazine instead of the drum magazine.

There was a show on the tube, the one with that perv guy, where they bubba’d up a later MP. 18-II to resemble this, so you might want to ensure that this is not the Bubba gun version.

It has a 1920 stamp on the receiver so it was used by the Weimar Police.

This comes with 2 drums with adapters and 1 drum loading tool. These drums are the same drums used with the Artillery Luger. This is C&R fully transferable and is currently on a form 3.

via German WWI MP18,I with 2 Drums & Loader : Machine Guns at GunBroker.com.

If you’re familiar with later German SMGs, the bolt and striker of the MP.18 look pretty familiar:

MP.18-I 25

The simplicity of this firearm was so elegantly perfect for its purpose that it spawned hundreds of work-alikes, few of which improved on its basic function (after replacing the overly complex magazine).

This may look like a lot of pictures, but there are way more at the auction link — something like 30 of them all told. You know you want to click over there anyway.

Sure, it’s more than our pickup cost, new, and it’s almost 100 years old. But on the other hand, our pickup will be worth approximately $0 in ten years, and an original MP.18-I is unlikely to lose much value. (If you buy it into a business you can even try depreciating it and see if the tax guys let you).

In case two drums aren’t enough for you, the same seller has a third, too. Without loader, but with dust cover. They’re all First Model snail drums. Annoy a totalitarian, buy a 32-round magazine.

third drum

One nice thing about this seller’s auctions is that they run for a good, long time. The MP.18 has eight days to go. (Serious bidders may not show up until close to the end. Don’t read too much into lack of bids on an auction when it still has weeks to run).

Another nice thing about these auctions? They give all of us the chance to see many rare collector pieces. We can’t own them all, but we can get eyes on them when they change hands. How cool is that?

How Did the FG-42 Selector Work?

We were asked that yesterday and we pontifically pronounced, “it fired from the open bolt in automatic mode, and from the close bolt in semi.”

This one's an SMG Guns semi clone. Pretty, though, innit?

This one’s an SMG Guns semi clone. Pretty, though, innit? Images do embiggen with a click.

Then we rested back on our laurels as Gun Expert and —

“Well, how did they make it do that?”

“*!” Hmm… How did they? “Let me get back to you on that.”

Fortunately, several references on the shelves explain it in terms our walnut sized brain could grasp. It turns out it was very simple, when you consider how complex some of the other design options made the FG. And it imposed some trade-offs, costing the rifle significant semi-auto accuracy as the price of that mechanical simplicity. Let’s walk you through it.

It worked exactly the same on the First and Second model of the FG, by the way; so we will use images of both in this post.

FG42-0034- grip FW

This image is from a crudely DEWATted Second Model FG that was examined by Forgotten Weapons. There’s a great set of images there, and the gun’s internals are mostly present and correct.

The selector switch is on the left side of what we’d call the grip frame. (The German manuals call this part the Lager which can mean holder or receiver, too, but we’ll stick with “grip frame”). The selector swings through 180º of travel; knob forward covers an “E” for Einzelfeuer (“single fire,” semi-auto), and knob rear clicks on to “D” for Dauerfeuer, (“continuous fire,” automatic). Note that the letter that shows is the antonym of the function you get. Don’t ask us; Hermann Göring was not available to take complaints.

FG-42 exploded view

Comparing the Bedienungsanleitung (manual) image of a First Model to the photo of the second model above that, we can see how the trigger works. The trigger pivots on a pin forward of, and slightly below, the selector switch. The axis of the selector switch is also the axle of the sear (in the diagram, Part B8 Abzughebel, literally “trigger lever”). The sear nose (Fangnase, “catch nose,” B8a) is the hardened end of the sear that engages a notch (if you learned engineering English in Britain, a “bent”) in the operating rod (Verschlußführungsstück, “bolt guiding piece,” Part D10).

There are, however, two notches in the op-rod. One is towards the front end, and mostly right of center. One is towards the tail end, and mostly left of center. You can make out the two notches in this Forgotten Weapons photo.

FG42-0003_FWRotating the selector moves the sear laterally either right to align with the front-end notch, or left to align with the tail-end notch. If it aligns with the tail-end notch, a disconnector (Unterbrecher, literally “interrupter”, B9), works by disengaging the trigger from the sear until the trigger is released (i.e., normal semi-auto trigger reset). Thus the selector engages the sear nose with either the nose-end notch, which holds the op rod and bolt assembly to the rear, or the tail-end notch, which holds the op rod and firing pin only to the rear, allowing the bolt to lock fully into battery.

Releasing the trigger releases the op-rod, then. If the weapon is on full automatic, the bolt and op-rod come forward, the bolt locks, the op-rod finishes its full travel, and the firing pin initiates the cartridge. The whole thing cycles again and continues to do so until the operator releases the trigger. When he does, the bolt is held in automatic battery — to the rear.

These schematics are from Allson & Toomey's Small Arms, pp. 226-227.

These schematics are from Allsop & Toomey’s Small Arms, pp. 226-227. The depiction of the selector in these drawings is how we came to understand that the selector (“change lever” in British English) covers the appropriate letter for type of fire selected.

If the weapon is on semi (selector knob swung 180º to the front), the trigger releases the op-rod, which brings the firing pin down on the primer. The bolt then cycles, but returns to semi-auto battery, closed bolt on a live cartridge, regardless of trigger position. The disconnector rides in the notch forward of the rear notch (here “bent”) only to disconnect when in Semi.

fg42mechanism13_11

If you’re feeling envious of FG-42s, you can buy an excellent semi repro from SMG Guns, you can pay more than a new luxury car for a transferable, or you can take the following image, a pile of steel, wood and aluminum, and a set of files and try to do what SMG did:

FG-42 Type II exploded view

It may take a while. Best of luck to you!

Now, the FG42 wasn’t the last word in open/closed bolt hybrid firing mechanisms. As mentioned, having the whole op rod and firing pin move was inimical to accuracy. This not only increased the motion of the firearm on firing, but it increased lock time substantially, giving that motion more time to work on sending your projectiles wild. But that was a tradeoff that designers at Rheinmettal accepted for their simple and reliable open/closed bolt mechanism.

As we’ve seen, waste heat is a real killer of combat weapons in automatic fire, and by extension, a potential killer of the men who fire them. Firing from an open bolt reduces the incremental temperature increase per automatic round fired, by allowing more air to circulate and more of the potential radiative area to be exposed to ambient-temperature cooling air. This has the side effect of moving the critical temperature area or point further up the barrel from its usual position 5 to 8 inches in front of the chamber.

Firing from an open bolt also prevents cook-offs. Contrary to common misconception, cook-offs are usually not instantaneous but result from a round remaining chambered in a hot barrel for some seconds or minutes. For a cook-off to be instantaneous (and risk an out-of-battery ignition) the temperature has to be extremely elevated. For a routine cook-off, which can take some time to happen, the biggest danger is that no one is expecting the weapon to fire, and people may be in an unsafe position forward of its muzzle at that point.

The FG42 was a remarkably good weapon, like many WWII German weapons. Not good enough for them to win the war, fortunately; it was the very devil to produce (ask Steve at SMG!) and was produced in the sort of numbers that would be a rounding error, or the scrappage involved in training some new line workers, in American, British or Russian production. The US produced, for example, about 40 times as many BARs as Germany produced FG42s; Russian production of the pan-fed DP28 LMG was easily double that. (German production wasn’t as dismal as you might think. They produced more rifles and carbines of all types than the USA did. But they did have a tendency to engineer something very good, and then fail to build it in numbers that would make a difference).