Sometimes all is not as it seems. That was the case when we examined this Steyr AUG. From the barrel and bipod it appeared to be an AUG in an HBAR or Heavy Barrel configuration but on closer inspection we found that it was in fact a rifle receiver, bolt and bolt assembly and chassis that had been paired with an HBAR barrel assembly.
Ordinarily, the HBAR could be modified to fire from an open, rather than closed, bolt. This example has the standard AUG progressive trigger for semi and full-auto. It does not have the modified bolt carrier, striker or trigger mechanism.
The HBAR has a 4x optic, rather than the rifle’s 1x, while the HBAR-T can be fitted with an optic like a Kahles ZF69 6×42.
Adoption of the AUG HBAR does not appear to have been widespread and Steyr don’t currently list it as an option amongst their upgraded AUGs. For more Steyr we have previously examined a Steyr AUG SMG conversion and a Steyr MPi 81.
Overall Length: 35.5in (90cm)
Barrel Length: 24.4in (62cm)
Weight: 8.6lb (3.9kg)
Action: Gas operated, rotating bolt – the HBAR typically fires from an open bolt, but this rifle-based example fires from a closed bolt.
Capacity: 30 or 42-round box magazines
Destroying railway infrastructure was a key mission for the Resistance groups and SOE agents active in occupied Europe. Numerous methods of damaging or destroying railways were developed, including Exploding Coal, which we have covered earlier in this series. In this 16mm colour footage, believed to have been filmed in 1940, we get an early look at the methods the SOE were developing to destroy track. The ultimate aim was to derail the locomotive and wreck the train with minimal effort and explosive.
In the footage we see two charges have been placed on the piece of track, with detcord attached to both. A soldier, with what appears to be a lever-action Winchester 94, is then seen taking aim. It seems he’s aiming at a striker board attached to ignite the detcord. He fires, we see a puff of smoke and a second later the charges detonate.
The footage then cuts to several men collecting the debris of the shattered piece of track. The track appears to have two large chunks blown out and the top edge, between the two charges, completely blown off.
Later in the war more testing was done and more refined techniques were developed. In their book SOE: The Scientific Secrets Boyce & Everett note that trials of devices and techniques for destroying railway lines carried out at Longmoor where the British Army had extensive sections of track and samples of rails used in different European countries. Trials to find the right quantity and positioning of explosive charges were carried out in late December 1943, these tests would inform later operations.
The SOE’s Descriptive Catalogue of Special Devices and Supplies includes a pair of illustrations demonstrating two methods of laying and detonating these charges. A so-called ‘French’ method with a pair of what the catalogue terms ‘Igniters, Fuze, Fog Signal, MkIA’ ahead of the charges in the direction the train was expected from. The train would crush these Fog Signals firing them and igniting a length of detcord linked to a pair of 3/4lb explosive charges fixed to the track as we see in this film.
The alternative ‘Polish’ method had the same sized and located explosive charges but placed a Fog Signal either side of the charges to ensure that no matter which direction the train came from the charges would be detonated. This method was used on single track stretches of railway. Both of these methods were rated to ‘remove about one metre of rail.’
In this photo we see a member of the French Resistance setting an explosive charge on a railway line. While likely a posed photo we do see the pair of Fog Signals which will stet the charge off. These photographs show a pair of trains reportedly derailed by explosive charges.
Boyce & Everett in their book SOE: The Scientific Secrets suggest that as many as 48,000 ‘Railway charges’, presumable a kit, were produced by the SOE. From the footage we can certainly see this method of destroying rails was effective.
Today, were taking a look at a Winchester prototype developed in the mid-1860s, a period when Winchester was seeking to build on the success of the 1860 Henry Rifle and place the company on a firm financial footing. Oliver Winchester had taken control of the New Haven Arms company before the Civil War and while for a time it had been known as the Henry Repeating Arms Company he eventually sought to put his stamp on the company, renaming it Winchester Arms Company in 1866. At the same time he decided to focus the company’s energies on winning military contracts around the world.
This developmental prototype is in the ‘musket’ configuration: with a longer barrel, a bayonet lug and a wooden forend. The prototype represents one of the many developmental steps towards what would become the Model 1866. It has a number of interesting features – a steel, rather than brass, receiver and a hinged loading port developed by Nelson King, Winchester’s superintendent between 1866 and 1875.
The rifle itself was built by Luke Wheelock, Winchester’s model room mechanic and a designer in his own right who would go onto develop his own rifle designs for Winchester.
The rifle is 54.5 inches long, with a 33.75 inch barrel. Believed to have been built in 1866, it is chambered for a .45 calibre rimfire round. King patented his loading port in May 1866. He described how the port worked:
“Through one of the plates S (preferring that one upon the right-hand side) I form an opening, 0, as denoted by broken lines, Fig. 1, and also seen in section, Fig. 7. This opening is formed so as to communicate through the frame directly to the chamber E in the carrier block, as seen in Fig. 3. Through this opening, and while the carrier-block is down and all parts of the arm in a state of rest, insert the cartridges, point first, through the said opening in the plate S into the chamber E the second cartridge pressing the first into the magazine, and so on with each successive cartridge until the magazine is filled, or until the requisite number has been inserted therein, the follower G being pressed up before the entering cartridges. In the rear of the chamber E2 the frame forms a shoulder to prevent the cartridges from being forced out through the opening in the plate S3 is a cover for closing the opening in the plate S3 and is hinged thereto, as seen in Figs. 1 and 7, the hinge being provided with a spring,a1, the tendency of which is to open the cover C. A spring-catch, d, (see Fig. 1,) secures the cover when closed, so that by pressing upon the said catch the cover will fly open. After the requisite number of cartridges have been placed within the magazine, close the cover, as seen in Figs. 1 and 2.”
To paraphrase: ammunition can be loaded through the opening in one of the receiver side plate when the carrier block is down, insert the cartridges through the opening, pressing the first into the magazine and so on until the magazine is filled… a cover for closing the opening is hinged to the receiver side plate. A spring catch secures the cover when closed.
According to Herbert Houze, King developed the covered loading port design in early January 1866, with a design drawing dating to the 14th January, confirming this.
King altered the design of the rifle’s cartridge carrier so that a cartridge could pass through its lower section straight into the magazine when the action was closed. In theory the aperture could be placed on either side of the receiver, in practice is was placed on the right. Prior to this Winchester had experimented with systems where the tube could slide forward (G.W. Briggs US #58937), a port in the base of the receiver (J.D. Smith US #52934) or a sliding forearm covering a loading port at the rear of the magazine tube (O.F. Winchester UK #3284 [19/12/1865]).
King’s system had the benefit of allowing the rifle to be quickly loaded or topped off without rendering the rifle unusable while loading. Positioning the port in the receiver allowed the magazine tube to be enclosed by a wooden forend.
A cartridge guide was fitted inside the receiver which guided rounds through the cartridge carrier and into the tube magazine. The rounds were prevented from popping out of the magazine, when the carrier was aligned and the cover open, by a shallow shoulder which projected in line with the carrier’s channel to hold cartridges in the tube by their rim.
The hinged cover is held shut by a spring catch mounted on the rear of the cover. When the knurled section on its front is pressed rearwards the cover pops open. The spring catch is actuated when it tensions against the cover’s hinge as it is closed. On the back of the cover there is also a cartridge stop for when the cover is closed.
Another small but interesting feature of the prototype is the catch at the rear of the lever loop, this differs from the manually turned catch seen on the Henry and production 1866. This design appears to be a much better safety feature, simply requiring the user’s hand to depress the catch to unlock it from the stock. It also appears to be a much simpler mechanism than that seen in later models like the Model 1895. The trigger also had an extension protruding from its rear which appears to prevent the trigger from being pulled when the lever isn’t full closed. Neither of these features appear in King’s May 1866 patent.
It appears that the idea of the port with a hinged cover was superseded by what we now recognise as the classic Winchester loading gate in the summer of 1866. King’s new system replaced the hinged cover with a piece of stamped spring steel attached to the inside of the receiver side plate by a screw. The spring steel gate could be pushed in, with the nose of a cartridge, to allow rapid loading. The front face of the gate formed a cartridge guide removing the need for the separate machined guide used in King’s earlier iteration of the system.
King’s revised loading port system required just five, rather than twelve, components: King’s altered cartridge carrier, receiver side plate, spring metal loading gate plate and retaining screws. This simple but elegant design continued to be used for decades on various models of rifle. The company were so pleased with the refinement of the rifle that, according to R.L. Wilson, King was awarded a payment of a $5,000 reward by the company’s board of directors.
Winchester introduced the rifle in 1866, with the first deliveries being made early in 1867, the new rifle was offered in various barrel lengths and patterns including carbine, rifle and ‘musket’. Winchester found some success selling 1866 rifles to the militaries of France and the Ottoman Empire, while many other countries purchased rifles for testing including Britain and Switzerland (whom came close to adopting the Winchester.) The rifles also found success on the civilian market with around 4,500 sold in the first five months.
The Scientific American described the new rifles as “elegant in appearance, compact, strong, and of excellent workmanship. On examination we find its working parts very simple, and not apparently liable to derangement.”
King incrementally developed his loading system before radically simplifying it and this prototype rifle represents an important developmental step in the design of what would become the Model 1866 – one of Winchester’s most important rifles.
Special thanks to the Cody Firearms Museum for allowing us to take a look at this fascinating prototype rifle.
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Winchester Repeating Arms Company, H. Houze (1994)
Winchester: An American Legend, R. L. Wilson (1991)
The footage, believed to have been filmed in 1940, is part of the Imperial War Museum’s collection, it shows plastic explosive being demonstrated in a number of different applications. It was filmed by Cecil Vandepeer Clarke, a British engineer and sabotage expert who was a member of the Special Operations Executive and worked at a number of weapon research and development centres during the war.
The clip features a number of men preparing and shaping plastic explosive charges, adding fuses and detonators. The explosive is then seen being applied to a steel plate in a ring shape, before being detonated. The resulting explosion punches a round hole through the plate. The film also includes demonstrations of what plastic explosive pressed against a tree trunk can do. Once detonated the roughly 1 foot thick trunk is splintered in two. Metal girders are also shown being prepared with a substantial block of explosive being pressed into its seams.
The SOE’s 1944 Descriptive Catalogue of Special Devices and Supplies lists the ‘Standard Charges’ of 1.5lbs or 3lbs of plastic explosive with an integrated central primer available in rectangular blocks inside a rubberised fabric. Of course SOE agents were taught to use as much or as little explosive as was needed for the task and they were taught to be able to improvise in any given situation.
Given the date of the footage the explosive being used is likely and early form of plastic explosive produced at Woolwich arsenal, possibly PETN or Cyclonite better known as RDX, which would have been mixed with a plasticiser to make the explosive malleable.
Today, we’re lucky enough to have some colour footage showing the of testing of a magnetic bomb which could be attached to the petrol tank of vehicles. The footage comes courtesy of the Imperial War Museum.
From the film we can see that the bomb consisted of a small block of plastic explosive, a pair of strip magnets (or possible a horseshoe-shaped magnet) and a Switch No.10 time pencil delay detonator. The explosive block itself looks to be slightly smaller than the SOE’s standard 1.5lb charge.
In the film we see the bomb placed on the boot (or trunk) of a saloon car before various civilians and a corporal experiment with various ways of covertly attaching the bomb to the underside of the car. At one point the corporal allows himself to be dragged along behind the vehicle before making his escape.
Luckily the 16mm footage, filmed by Major Cecil Clarke, also shows us the effect of the explosive charge mounted on a petrol tank full of fuel. According to the details listed for the film by the Imperial War Museum the footage was filmed in 1940, at SOE Station XVII, located at Brickendonbury House in Hertfordshire.
This configuration of the bomb doesn’t appear in the Special Operations Executive’s Descriptive Catalogue of Special Devices and Supplies published in 1944. However, Colonel Leslie Wood, Station XII’s commanding officer, described the demonstration put on during a visit by Brigadier Robert Laycock of the Commandos and William Donovan, the head of the American OSS in June 1942. One of the scheduled demonstrations was the “Effect of small ‘magnet’ charge of explosive on petrol tank of car.”
It appears that this ad hoc magnet charge evolved into ‘the Clam’, which was a smaller, version of the magnetic Limpet mine. The Clam evolved through a number of marks with the MkI having a stamped sheet metal casing and the later MkIII using a bakelite, plastic casing. Both were made up of a plastic explosive charge inside a rectangular, rounded case with a pair of magnets at either end. They were detonated by either a Time Pencil or an L Delay fuse attached to a No.27 detonator. The MkIII had 8oz (226g) of high explosive filler, such as TNT/Tetryl 55/45.
While unlike the larger Limpet they weren’t developed for under water use but the Clam could be mount onto any vaguely flat magnetic surface including engine blocks, fuel tanks, crank cases, cylinder blocks, rail tracks and steel plate.
At just 5.75” x 2.75” x 1.5” they were easily concealable, could be carried in a pocket and were non-descript enough not to draw attention. An estimated 68,000 Clams were made under supervision at Aston House according to Des Turner’s book on Station XII.
The M50 is one of the quintessential early Cold War submachine guns. Cheap, simple and utilitarian. It evolved from the earlier M46 and was developed by Dansk Industri Syndikat in Denmark. The M50 has a simple blowback action, is chambered in 9×19mm and feeds from 32-round double stack single feed magazines.
The weapon’s has a clam-shell like receiver that hinges at the rear and allows the barrel, bolt and recoil spring to be removed. The M50’s folding stock has a leather cover and while the length of pull is a little short it provides a decent cheek weld.
The M50 has a relatively slow rate of fire of around 500 rounds per minute which makes it very easy to make single shots while in full-auto. The sights are extremely simple with a single rear peep sight.
It has manual safety switch on the left side of the receiver which locks the sear in place and a spring-loaded grip safety just behind the magazine well. The amount of pressure needed to disengage it is minimal and a firm firing grip of the magazine is all that is needed.
The Madsen went through a number of changes with various models having different magazine release types, selectors and manual safety positions. The M53 introduced in 1953, fed from a curved magazine and had an improved magazine release. Some models had an additional fire-selector and the safety moved back above the trigger. Some models retained the forward grip safety while others moved it to behind the pistol grip. Some patterns of M53 also had a barrel shroud for mounting a bayonet as well as added wooden panels on the pistol grip.
We’ll have a more in-depth look at the Madsen M50 in the future looking at the various models in some more detail.
Special thanks to my friend Chuck at Gunlab for letting me take a look at his M50.
We’re lucky enough to have some unique colour footage showing the of testing of some of these explosive devices and in this article we will examine an incendiary-filed case.
In this piece of 16mm colour footage, filmed in 1940 by Captain Cecil V. Clarke, we see what appears to be an attaché case containing three medium-sized bottles, which likely contains a mix of petrol and paraffin or some white phosphorus, prepared for testing at the bomb range at Brickendonbury in Hertfordshire, a Special Operations Executive training and research centre codenamed Station XVII. It’s believed that these films may have been produced as teaching aids for the agents trained at Station XVII and this film may have been shown during a lecture.
While incendiary briefcases, attaché cases and even suitcases are listed in the 1944 SOE Descriptive Catalogue of Special Devices and Supplies they were quite different from this case. They were primarily designed for the quick destruction of documents and items carried inside them. They used sheets of potassium nitrate to burn the case’s contents.
The incendiary case seen in this footage on the other hand appears to be designed to be clandestinely placed and detonated with a delay fuse, to set nearby flammable objects on fire. What was described as a ‘Delayed Action Incendiary’.
In this footage of another separate test we get an idea of the destructive capability of just one of the bottles.
It’s possible that this incendiary case was a proof of concept test for the later cases or perhaps a demonstration of a concealed incendiary device Station XVII were working on. SOE developed a large number of bespoke explosive devices for various missions, so while this device may not have become ‘standard issue’, it may have been developed for a specific purpose.
During the Second World War Britain’s Special Operations Executive (SOE) developed a whole series of sabotage devices for use behind enemy lines. Using unique archival footage this series of short videos examines some of the weapons developed for use by SOE agents in occupied Europe. We begin the series with a look at the history and development of Explosive Coal. Explosive coal was designed to explode inside fireboxes, furnaces and coal stores hampering enemy infrastructure.
I came across this footage while doing some research in the Imperial War Museum’s online catalogue. This piece of 16mm film was filmed by Cecil Vandepeer Clarke, a British engineer and sabotage expert who was a member of the Special Operations Executive and worked at a number of weapon research and development centres including MD1 at Whitchurch and SOE Station XII at Aston.
SOE or Special Operations Executive were a clandestine force tasked with conducting irregular warfare behind enemy lines including sabotage, assassination, intelligence gathering an small scale raiding. One of the sabotage methods developed was introducing an explosive charge into the boiler firebox of a ship or a locomotive or a power station or factory’s furnace. This achieved by disguising the explosive as either a piece of fuel like coal or wood or even as a dead rat – which might be tossed into a firebox or furnace to be disposed of.
The idea of ‘Explosive Coal’ wasn’t new. The idea originated from the US Civil War, when Confederate Captain Thomas Edgeworth Courtenay designed a piece of cast iron, with a cavity which could be packed with gun powder, that looked like a lump of coal. The Courtenay described them as ‘Coal Torpedoes’, their aim was to damage a steam ship’s boiler enough to cause a catastrophic secondary explosion. While several vessels may have been damaged or sunk by these Coal Torpedoes, the claims are difficult to confirm.
It seems the idea of a coal bomb was resurrected in 1940 and initially a ‘Coal Borer’ was developed and available for use in theatre by mid-1940. The borer could be used by agents to make holes in lumps of coal which could be filled by plastic explosive and a detonator. This was soon superseded by an Explosive Coal Kit which included moulded fake coal and paints to allow agents to match the colour of local coal. The kit included instructions on how to prepare and use the coal bomb.
Arthur Christie, a lab assistant at Station XII, is quoted at length in Des Turner’s book on Station XII. Christie remembered being asked to drill large holes in some coal:
“Another task was collecting the biggest lumps of coal that I could find in the storeroom and taking them to the lab. I had no idea what they wanted them for; it was seldom explained to me and, when it was, it was often as clear as mud. My instructions were to try to drill a large hole in each piece of coal without shattering it. I tried with a brace and a six-inch long tube that had a serrated end. I found that, if too much pressure was applied, the coal would disintegrate. I thought, I wonder what the hell they want this for? Don’t ask, just do it, and I did manage to drill three lumps of coal. I placed the drilled coal on the table of the MI room and set off for the officers’ dining room to inform the CO that I had been successful. I was told to insert about a quarter of a pound of PE and a detonator into the hole and glue the coal dust back over it. The mud in my brain now began to clear. The lump of coal could be placed in the coal tender of a locomotive and find its way into the firebox, or perhaps into the furnace of a factory. Later the PE was dyed black, which was better than using coal dust and glue. This idea led to plastic explosive being moulded into a multitude of objects and colours to fool the enemy.”
Frederic Boyce & David Everett, in their book SOE: The Scientific Secrets, credit Station XV with the development of a moulded clam-shell design using dyed Herculite plaster and coated with real coal dust. A photograph of this can be seen in the SOE’s Descriptive Catalogue of Special Devices and Supplies, along with ‘Explosive Wood’, or as it was officially known ‘Wooden Logs, Explosive’.
Eventually this was replaced by a bomb based around a charge in a metal casing that allowed liquid plaster to be poured around it, simplifying production and removing any sign of a seam. The coal bombs were detonated by a No.27 Detonator to which either a match headed safety fuse or a time delay fuse was attached.
Once the danger of coal bombs was discovered by the enemy it was also believed that they would have considerable a psychological impact and also cause the enemy to expend considerable resources on protecting and checking coal supplies.
The ‘Explosive Coal’ we see in the footage appears to actually be an incendiary bomb, producing a large amount of flame and heat. This would have been ineffective in a boiler but with a time delay or other sort of fuse it may have been very effective in causing a coal bunker fire aboard a ship, in a factory store, at a coal depot or in a locomotive’s coal tender. Coal fires are extremely difficult to contain and put out.
How effective Explosive Coal was is unclear but it is believed that coal bombs were used by both the SOE and their American counterparts the OSS. Boyce & Everett estimate that about 3.5 tons of explosive coal was made between 1941 and 1945. I’m unsure how many of these were explosive and how many were incendiary, like that seen in the footage here, but it’s a fascinating asymmetric method of targeting enemy infrastructure at the most basic level.
The Diemaco M203A1 is a development of the M203 40x46mm low velocity grenade launcher. The M203 was initially developed by AAI to replace the Colt XM148 which proved overly complex when tested in Vietnam.
The Diemaco M203A1 improves on the earlier launcher by incorporating its sight into the mount rather than being atached to the top of the barrel. The Diemaco M203A1 should not be confused with the Colt-manufactured M203A1 in US service. The Diemaco launcher is offered alongside the C7 and C8 rifles made by Diemaco (now Colt Canada).
Diemaco developed the M203A1 so it has a longer action, with the breech opening further to allow the firing of all 40×46 mm LV grenades including less than lethal baton rounds. It can also be mounted on all AR-patterned rifles as well as the Steyr AUG.
Like the original M203 the launcher can be operated by either a left or right handed users. The original model had an iron sight assembly has dual azimuth adjustment knobs and an elevation dial, this model, however, has a simplified tangent sight. Diemaco stated that the M203A1 has a maximum effective range of 400m (440 yd) with a muzzle velocity of 78 m/s (260 ft/s).
The M203A1 was tested by the UK’s special forces in the late 1990s, when they evaluated the Diemaco SFW carbine, which was subsequently adopted as the L119A1. The Heckler & Koch M320 GLM (HK AG36) has since been adopted by the British Army.
Calibre: 40 mm
Loaded Weight: 2.15 kg (4.74 lb)
Empty Weight: 1.85 kg (4.08 lb)
Overall Length: 318 mm (12.52 in.)
Barrel Length: 228.6 mm (9 in.)
Overall Height: 140 mm (5.51 in.)
Rifling: Right Hand Twist – 6 Lands
Rate of Twist: 1 turn in 48 in. (121.9 cm)