Heckler & Koch HK33

Heckler & Koch’s first 5.56×45 rifle, the HK33, was introduced in the late 1960s as a response to the emergence of the new 5.56x45mm round and the introduction of the FN CAL. The HK33 is little more than a scaled down version of HK’s successful 7.62×51 G3. Developed by Tilo Möller, the HK33 used the same roller delayed blowback action and shares most of the G3’s features.

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Left & right views of the HK33 (Matthew Moss)

It has a stamped receiver and uses the same plastic furniture and pistol grip/trigger mechanism housing as the G3. The rifle is 39 inches or 92cm long and is by no means a light weapon, weighing around 4kg or 8.7 lbs. The HK33 feeds from 25, 30 or 40 round proprietary HK magazines.

The rifle came in main two main variants a full length version with a fixed stock, which could be fitted with a collapsing stock, and a shortened K-variant with a shorter barrel. The weapon came with either a safe, semi and full auto or safe, semi, 3-round burst fire control mechanism.

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HK factory brochure showing the variants of the HK33 (Heckler & Koch)

The HK33 was not adopted by the West German Army, however, it did see extensive use with Germany’s federal state and police forces and the Bundeswehr special forces. While it wasn’t adopted at home it was a successful export weapon with dozens of countries purchasing and adopting the rifle. France tested the improved HK33F in the Army 1970s and although it performed well the FAMAS was adopted instead. A production license was sold to Thailand who adopted the HK33, purchasing 40,000 rifles and the license to manufacture 30,000 more. Thailand also developed their own unique bull pup version of the rifle, the Type 11.

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HK33 field stripped (Matthew Moss)

Malaysia also purchased 55,000 HK33s and the Spanish Guardia Civil used them for a time. The manufacturing rights for the HK33 were also sold to Portugal for production at Fabrica Militar de Prata and to Turkey where it remains in production at MKEK.

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A comparison of the HK33’s bolt with the later HK G41 (Matthew Moss)

HK produced the HK33 from 1968 through to the late 1980s. It also provided the basis for the HK53 5.56 ‘submachine gun’ which we have covered previously. It was also the basis of the less successful G41, which we’ve also covered in a full length episode, you can find this here. The similarities with the HK33 are easy to see but the G41 has a number of subtle changes.

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Specifications (from 1985 factory brochure):

Overall Length (with fixed stock): 36in /92cm
Barrel Length: 15.7in / 40cm
Weight: 8.7lbs / 4kg
Action: Roller-delayed blowback
Capacity: 25, 30 or 40-round box magazine
Calibre: 5.56x45mm


Bibliography:

Full Circle: A Treatise on Roller Locking, R. Blake Stevens (2006)

HK33 Factory Brochure, c.1966 (source)

HK33E Factory Brochure, c.1985 (source)

Colt CGL-4 (XM148) 40mm Grenade Launcher

Here’s Vic’s video on the XM148, check out Matt’s article below:

There have been attempts to fire grenades from the infantryman’s weapon since the 17th century. Up until the 1960s these almost entirely involved muzzle attachments or grenades which could be fired off the end of a rifle’s barrel. In May 1963, the US military called for a new ‘underslung’ grenade launcher to complement the AR-15/M16, then in early testing. The grenade launcher program had its roots in the ultimately unsuccessful Special Purpose Individual Weapon (SPIW) program which had begun in 1952.

While a series of designs were developed by various manufacturers and designers, May 1964 saw Colt unveil the CGL-4. The Colt was tested against designs from Springfield Armory and Ford, a design from AAI was promising but it was not able to chamber the 40x46mm rounds used by the M79 and was rejected. The US military sought munitions commonality between the M79, already in service, and the new rifle-mounted grenade launcher.

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Left side view of the XM148’s bulky tangent sight (Vic Tuff)

In March 1965, the CGL-4 was chosen for further testing and a contract for 30 launchers was signed. The CGL-4 was reportedly developed by Karl Lewis and Robert E. Roy in just 48 days. However, the design was complex. To load the barrel housing slid forward allowing a grenade to be placed in the breech, the weapon was then cocked and a long trigger, which projected back towards the rifle’s trigger guard, could be pulled to fire the weapon.

CGL4 Patent
Karl Lewis & Robert E. Roy’s patent for the Colt CGL-4 (US Patent Office)

Despite some problems with barrel housings cracking an order for 10,500 of the new launchers, now designated the XM148, was placed in January 1966. Production capacity issues and problems with the launcher’s sight lead to production delays and it wasn’t until December 1966, that the first shipment of 1,764 launchers arrived in Vietnam for field testing.

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Right side view of the XM148’s trigger, cocking mechanism and pistol grip (Vic Tuff)

Initial reports from the field were promising with troops praising the “tactical advantage of both the point fire and area fire system” concept. The XM148 was well received by the SEALs and the Australian SAS. The armourers of the Australian SAS, deployed to Vietnam with the 1st Australian Task Force, were also hard at work attaching XM148s to L1A1 rifles. Removing the L1A1′s handguard and attaching the XM148 to the rifle’s barrel.

Field testing was carried out by 12 units from six different divisions which were operating in various parts of Vietnam. This gave a wide variety of terrains and yielded some interesting results. In general it was found that the XM148 decreased rate and quantity of the grenadier’s fire, it slowed his reaction times when firing at a target, it hampered his movement in dense vegetation and also meant the grenadier had to spend longer caring for his weapon.

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XM148 with breech open (Vic Tuff)

It was noted that the sight mount which was overly complex and prone to snagging on brush and kit, it was also felt that too much force was needed to cock the XM148 (around 30 lbs) and the trigger mechanism was felt to be overly complex and difficult to repair and disassemble. One safety concern was the XM148′s long trigger bar, which could snag and launch a round – not ideal for special forces patrols infiltrating through thick bush. Problems with the launcher’s quadrant sights also continued causing deflection errors out at longer ranges. The bulkiness of the sights exasperated these problems as when they were knocked the XM148′s zero could be effected. The XM148 also precluded the use of a bayonet as when fired it would blow the bayonet off the muzzle. Overall, troops felt the XM148 was too fragile and complex for use in the field.

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SP4 Willey firing an M16A1 mounted with a Colt XM148 c. 1967 (US National Archives)

At least one unit found use for the launchers, the 1st Cavalry Division (Airmobile)’s Operational Report for Quarterly Period Ending 31 October 1967, noted that the XM148

“proved unsatisfactory in infantry units due to its lack of durability; consequently, USARV directed that they be turned in. However, 1/9 Cav has devised a method of mounting the launcher coaxially on the M60C machine gun used by scout observers on OH-13 scout helicopters. Durability in this environment is
not a problem since the weapon deos not receive the rough handling it did in the hands of ground troops. Firepower on scout helicopters is significantly increased. Fifty-two XM148s have been retained for use by 1/9 CAV.”

Finally, despite Colt’s efforts to rectify the growing list of problems the Army Concept Team In Vietnam deemed the XM148 unsatisfactory for deployment in Vietnam and recommended they be removed from service and a new improved launcher be developed. This was a massive blow to Colt who had already manufactured 27,400 XM148s. Many of these were already in Vietnam.

The US Army launched the Grenade Launcher Attachment Development (GLAD) program in the summer of 1967. A large number of manufacturers submitted designs including Colt, who offered the improved Henry Into-designed CGL-5. The Army turned down Colt’s offer of 20 free improved launchers and rejected the CGL-5 outright. The GLAD program saw the resurgence of the earlier AAI design, designated the XM203, this simple design, now chambering the 40x46mm shell, was eventually selected in August 1968. Ironically, as AAI was predominantly a research and development company and after an initial run of 10,000 made by AAI, Colt was subsequently awarded the contract to manufacture the M203 from 1971 onwards.

CGL-5
Harold Into’s patent for the product improved CGL-5 (US Patent Office)

While the XM148 proved to be a failure it played an important role in proving the operational viability of the rifle mounted grenade launcher system. The muzzle-launched rifle grenade is all but obsolete, superseded by the under-slung grenade launcher.

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Specifications:

Length: 16.5 inches
Weight: ~3lbs
Calibre: 40x46mm
Action: single shot, striker-fired single action
Capacity: 1
Rate of Fire: ~4 rpm


Bibliography

Images: 1 2 3 4 5 6

Black Rifle, E.C. Ezell & R. Blake Stevens, (1987)

Colt Industries Newsletter, Vol.2 no.3, May 1967, (source)

‘Grenade launcher having a rotatable forwardly sliding barrel and removable firing mechanism’, US Patent #3507067, H.A. Into, 14/12/67 (source)

Operational Report for Quarterly Period Ending 31 October 1967, 1st Cavalry Division (Airmobile), (source)

‘Grenade launcher’, US Patent #3279114, K. Lewis & R. Roy, 25/09/64 (source)

Springfield Armory Database entries: 1 2 3

40mm Shoulder-Fired Grenade Launchers & the SEALS, Small Arms Review, K. Dockery, (source)

The XM148: Birth of the Mounted 40mm Grenade Launcher, Small Arms Review, J. Wong, (source)

My thanks to Daniel Watters for information on AAI & Colt M203 production contracts. 

Heckler & Koch G41

In 1981, Heckler & Koch introduced what would be their last infantry rifle that used their tried and tested roller-delayed blowback action, the HK G41. In October 1980, following NATO’s smalls arms and ammunition testing during the late 1970s, a meeting of NATO Armament Directors, agreed to standardise to the 5.56x45mm round favoured by the United States since the mid-1960s. Standardisation Agreement (STANAG) 4172 saw NATO standardise on the Belgian/FN SS109 ball round. At the same time Draft STANAG 4179 proposed adopting US 30-round M16 magazines as the standard 5.56 magazine pattern, while this proposal wasn’t ratified the M16’s magazine became the de facto standard.

At this time Heckler & Koch were engaged in a major engineering project to develop the G11 caseless ammunition-firing individual weapon. Their main offering for the 5.56x45mm rifle market at the time was the HK33, a rechambered version of the 7.62x51mm G3 developed by Tilo Moller, which was introduced in 1965. The HK33, however, used a proprietary HK magazine and was not compatible with the M16’s magazines. In 1977, as the NATO trials began and it became clear that 5.56x45mm would be adopted, HK began to develop what would become the G41. In 1979 with initial development completed HK submitted 18 G41s for testing with the West German Army. It wasn’t until 1981 that HK introduced the G41 onto the market.

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Left and right profile views of the G41 (Matthew Moss)

While continuing to use the same roller delayed blowback operating system as the G3, HK33 and MP5, the G41 embodied a number of improvements. While still using a stamped metal receiver it utilised 1mm thick high tensile steel rather than the 1.2mm thick steel used by the HK33. This helped to lighten the receiver. The new rifle also used a lighter bolt assembly, paired with a new recoil spring which comprised of five wound strands around a central coil, rather than a single coil, which had a longer stroke. This acted to lower the felt recoil. The G41, however, had a higher rate of fire at around 850 rounds per minute compared to the 750 rounds per minute of the HK33.  Some of the G41’s bolt geometries were reworked and a new extractor was added.

The G41’s lower receiver was redesigned to allow the rifle to feed from STANAG magazines rather than HK’s earlier proprietary magazines. The cocking lever and forward assist were taken from the HK21A1 (XM262) general purpose machine gun, developed for the US SAW trials.

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HK G41 (top) and HK33 (bottom) field stripped (Matthew Moss)

It also had a new more triangular polymer foregrip and added a plastic dust cover to the ejection port, a NATO pattern optics mount (meeting STANAG 2324) replaced HK’s claw-mount system, and a spring-loaded folding carrying handle near the centre of balance was added. Importantly it also added a last round hold open device and a bolt release catch, on the left side of the lower receiver.

The usual thumb serrations on the side of the bolt, for pushing the bolt home, were replaced by a prominent forward assist, similar to that found on the M16A1 and other HK weapons such as the HK21 light machine gun and the PSG-1 sniper rifle. HK sales literature described it as a ‘low noise’ forward assist and the manual describes the “quiet cocking of the weapon” – essentially riding the cocking handle back into battery and then pushing the forward assist to lock the action, the system is not as ‘low noise’ as advertised.

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Right side of the G41, note the addition of a forward assist and dust cover (Matthew Moss)

Another important feature of the rifle was the inclusion of a three-round burst setting alongside semi and fully automatic. The G41 could mount a standard G3 bayonet, fit an M16 bipod and had a flash hider designed to enable it to fire NATO standard rifle grenades. The 40mm HK79 under barrel grenade launcher could also be mounted to all variants of the G41, simply swapping it out for the polymer forend. HK referred to this set up as the G41-TGS or ‘Tactical Group Support system’.

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Spread from a 1985 HK promotional product brochure showing the various G41 configurations (HK)

The G41 came in a number of variants with designations A1 to A3. The base rifle had a fixed buttstock and its rifling had 1 turn in 7 inches with a right-hand twist, in a 18.9 inch barrel. The A1 had a 1 in 12” twist barrel and fixed buttstock. The A2 had a collapsing, single position stock and 1 in 7” inch twist rifling, while the A3 had 1 in 12” inch twist rifling. The 1 in 7” rifling was optimised for the new SS109, while the 1 in 12” optimised for the US M193 round. There was also a shortened G41K model which had a collapsing stock and a 15 inch barrel available with both rifling types.

One of the main issues with the G41 was its weight. Despite efforts to lighten the sheet metal receiver, it weighed more than its predecessor the HK33. According to measurement data compiled by researcher Nathaniel F, unloaded the G41 weighs in at 4.31kgs or 9.5 lbs, this is a full pound heavier than the HK33. A contemporary M16A2 weighed 3.39kg or 7.5 lbs while the Spanish CETME L, a similar stamped receiver rifle chambered in 5.56×45, weighed 3.72kg or 8.2 lbs. The rifle eventually adopted by the Bundeswehr, the HK G36, weighed 3.13kg or 7.3 lbs.  The G41K with its collapsing steel stock wasn’t much lighter, weighing 4.3kg or 9.5 lbs, according to HK sales literature. Another potential issue may have been reliability with the move to the STANAG magazine rather than the optimised proprietary HK magazines may have introduced some issues.

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The bolts of the HK G41 (top) and HK33 (bottom), note the redesigned extractor, forward assist serrations on the bolt carrier and the G41’s thicker but shorter recoil spring (Matthew Moss)

Following NATO’s decision the early 1980s saw a large number of countries looking to replace their ageing 7.62x51mm battle rifles. Sweden began to look for a 5.56x45mm rifle to replace its licensed version of the G3, the Ak4, in the late 1970s. HK could initially only offer the HK33 but the G41, tested later, was also rejected by the Swedes in favour of FN’s FNC. Italy sought to replace the BM59 with a more modern rifle and HK entered into an agreement with Luigi Franchi which saw them offer both the original HK configuration and the develop their own, slightly modified version, the Franchi mod. 641, but the Beretta AR70/90 was selected. Similarly, in 1984 Spain decided to adopt the indigenously developed CETME L. In 1986 the HK G41 was also submitted to the Irish Army’s trials to replace the FN FAL, it was beaten by the Steyr AUG. Initially West Germany had hoped to procure up to 20,000 HK G11 rifles per year, with a total of 224,000 in service by 2003.

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HK’s G11 and G41 (Matthew Moss)

The collapse of the Soviet Union and the subsequent reunification of Germany saw Federal budgets stretched and the G11 programme was subsequently abandoned entirely. The Bundeswehr still needed a suitable rifle to replace the G3 and in the 1990s sought a lighter weight rifle. HK felt their HK50 project, in development since the mid-1970s was a better bet than the heavier G41, and following Bundeswehr trials the G36 was subsequently adopted in 1997. Sadly, I have not been able to get a hold of any of the trials reports from the nations that tested the G41, so can not say with certainty why the countries mentioned above rejected HK’s rifle.

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Graphic from HK’s manual for the G41 (HK)

From photographs of members of the Turkish Gendarmerie special operations group training at the Foça Commando School, dating from the early 2010s, it appears that Turkey either purchased a number of G41s or Turkey’s state-owned defence manufacturer, MKEK, produced an unknown number under license.At some point in the 1980s the British Army also tested a small number G41s with serial numbers #11131, #11832 and #11833 remaining in UK collections.

Denmark’s elite Jaegerkorpset and Froemandskorpset used the G41 for a time and Argentina’s special forces, including the Grupo de Operaciones Especiales, have also been photographed with both HK G41s and G41A2(collapsing stock) fitted with the TGS package comprising of the HK79 under barrel grenade launcher.

Argentine commandos with HK G41
Argentina’s Grupo de Operaciones Especiales on parade with G41s and the G41-TGS, grenade launcher package (source)

The G41 represents the last evolution of HK’s infantry rifles using the roller delayed blowback action. It comes from a period when HK were developing what they hoped would be the next generation of small arms technology and with the collapse of the G11 programme and the lack of interest in the G41 the company faced financial uncertainty throughout the early 1990s. HK’s move away from the roller delayed blowback action to a more conventional gas operated rotating bolt system, combined with lightweight polymers, in the G36 proved to be more successful than the ill-fated G41.

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Specifications (standard G41 rifle model):

Length: 39in (99cm)
Weight (unloaded): 4.31kgs or 9.5 lbs
Barrel Length (not including flash hider): 17.7in (45cm)
Action: Roller-delayed blowback
Calibre: 5.56x45mm
Feed: 30 round STANAG magazines
Cyclic Rate: ~850rpm


Bibliography:

The World’s Assault Rifles, G.P. Johnston & T.B. Nelson, (2016)

Die G11 Story, W. Story, (1993)

Full Circle: A Treatise on Roller Locking, R. Blake Stevens (2006)

The 5.56 Timeline, D. Watters, (source)

1985 HK Brochure on the G41 Series (via SAR Archive)

HK G41 Owner’s Manual (via SAR Archive)


Our thanks to the collection that holds this rifle for their kind permission to examine and film it. Please do not reproduce photographs taken by Matthew Moss without permission or credit. ©The Armourer’s Bench, 2019.

The CETME AMELI Light Machine Gun

The CETME AMELI was developed by Spain’s state-owned small arms institute, Centro de Estudios Técnicos de Materiales Especiales or CETME. It was an attempt to develop a light machine gun chambered in 5.56x45mm. Its name, AMELI, is an acronym for ‘Ametralladora ligera’ – simply Spanish for light machine gun.

Development of the AMELI began in 1974 under the supervision of Colonel José María Jiménez Alfaro (who would later become the director of CETME). The Ameli was officially unveiled in 1981 and after undergoing exhaustive military trials was adopted into service in 1982 as the standard squad-level support weapon of the Spanish Army under the designation MG 82. It was manufactured by the Santa Bárbara National Company (now General Dynamics Santa Bárbara Sistemas) at the La Coruña factory.

Centrefire automatic machine gun - CETME Ameli (about 1982) (1)
Early NA or standard model AMELI (Royal Armouries)

The initial model was the NA variant, or Standard Model. This is the model that closely resembles the MG-42 with its conical flash hider. The Spanish military, however, wanted a lighter gun and the NB variant was designed, this is easily identified by the straight flash hider that is now integral with the barrel and not part of the barrel shroud.  The NB model reduced the unloaded weight from the original 7.24 Kg (16 lbs) to 5.4 Kg (12 lbs). However, this weight reduction and the use of materials of lower cost than the original trialled guns caused reliability issues with the AMELI in service. Both variants had a rotating rear disk sight, graduated from 300 to 1,000 metres, and a folding front sight. A mounting block for a British SUSAT optic was later added to the top cover.

Ameli with Winter Trigger Group
Detail view of the AMELI’s receiver from a factory brochure, also featuring the transparent belt boxes which did not go into service (source)

Parts breakages and stoppages plagued the AMELI in service and gunners had to take great care of their weapons to keep them serviceable. One issue was that the stamped forward barrel shroud was a press fit over the receiver and held in place by steel ‘barbs’. Rough handling and downward pressure on the bipod during manoeuvres and firing caused the shroud to deflect, this caused accuracy and functionality issues. To alleviate these problems the Spanish Marines went so far as to TIG weld the forward barrel shroud to the receiver, this fixed most of those issues.

The AMELI’s shape resembles the MG42 machine gun but the similarities are external only. While the MG42 uses the short recoil, roller locked system (where the barrel and bolt recoil together a short distance before separating), the AMELI employs a roller-delayed blowback action with a fixed barrel and a fluted chamber. This system was also used in the CETME Model A, B, C and L rifles, as well as in the HK G3 rifle, the HK 33 rifle and the HK MP5 submachine guns. Similarities with the CETME Model C and Model L rifles are limited to the commonality of the takedown pins and no other parts contrary to popular myth!

Centrefire automatic machine gun - CETME Ameli (about 1982)
Later NB variant of the AMELI – note also the different pistol grip profile, more similar to a CETME L rifle’s (Royal Armouries)

Both AMELI models have similar rates of firing of around 1,000 rounds per minute. The AMELI used the same feeding system used in the MG42, it had a cross bolt safety located at the rear of the top of the pistol grip and a quick change barrel system. To remove the barrel you pull the two sides of the barrel latch, which is built into the rear sight assembly, rotate the handle clockwise until the gate in the side of the barrel shroud opens and then pull the barrel back out of the gun. The front of the barrel is secured by a round ball detent which clicks into the front of the barrel shroud.

CETME also developed a top feeding magazine adaptor system, perhaps inspired by the contemporary FN Minimi’s ability to feed from magazines as well as a bolt. The Bren-like adaptor allows a STANAG magazine to be loaded in upside down into the action. To fit the adaptor the gun’s top cover and feed tray had to be removed. To deal with the magazine housing now obscuring the front sight the adaptor had a new set of sights – one at the rear and a new ‘front’ sight built into the side of the magazine housing, a little like the Australian F1 submachine gun. This short sight radius isn’t too practical for a light machine gun.

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A still from the video showing the top feed magazine adaptor’s sights, note they’re offset to the right and the protected front sight is built into the magazine housing (Vic Tuff)

The AMELI was sold to only a few operators apart from the Spanish Military, the Mexican Army and the Malaysian PASKAL Naval Special Forces have used the AMELI but the current status with those operators is unknown. In Spanish service the Ameli has almost entirely been withdrawn from service, being replaced with the Heckler & Koch MG4 5.56x45mm LMG. This is partly due to reliability issues and the original guns being worn out and with spares and new guns no longer available as the original manufacturer ceased manufacture in 2013 and went out of business.

Mexican Army Ameli
Mexican Marines with an NA model AMELI (source)

The AMELI is an interesting machine gun that should have had more success than it did. It was sadly a victim of government cost cutting which much like the British SA80 undermined the quality of the finished product. The story of the AMELI also reminds me of the ArmaLite AR10 produced by Artilleries Inrichtingen in the Netherlands, in so much as the AMELI was produced in very limited numbers (around 3-4,000 guns), in various models and variants with no clear defined history as to why aspects of the design were changed. Evidence of this was seen when a very good contact of mine bought up all remaining inventory from the CETME factory some years ago including around 30 Ameli’s. Apparently there were variations between every one they bought!

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Specifications (from CETME brochure):

Length: 97cm (38.2 inches)
Weight (unloaded):  NG: 6.7kg (14.8 lbs) NB: 5.2kg (11.5 lbs)
Barrel Length: 40cm (15.8 inches)
Action: Roller-delayed blowback
Calibre: 5.56x45mm
Feed: 100 or 200 round belts
Cyclic Rate: 900-1,250 rpm


Bibliography:

CETME AMELI Operator’s Manual, Small Arms Review Archive, (source)

CETME AMELI Early Factory Brochure (Spanish), Small Arms Review Archive, (source)

CETME AMELI Factory Brochure – including both models (English), Small Arms Review Archive, (source)

CETME AMELI Factory Flyer (Spanish), Small Arms Review Archive, (source)

 

Winchester Experimental Submachine Gun

Held in the collection of the Cody Firearms Museum (CFM), at the Buffalo Bill Centre of the West, is a most intriguing Cold War submachine gun. The weapon came from the collection of the old Winchester Firearms Museum, which the CFM inherited, it is not a test & evaluation weapon made by another company but a submachine gun designed and developed by Winchester. Those who know their Winchester history will know the company had no prior background in submachine gun design, instead being best known for their rifles and shotguns.

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Left side profile view of the N4 and N2 Winchester submachine gun prototypes with their stocks folded (Matthew Moss)

Very little is known about Winchester’s submachine gun project, but two prototype examples survive, an early ‘in the white’ model labelled ‘N2’ and another which Herbert Houze, the CFM’s former curator, designated ‘N4’ . The documentary evidence for the Winchester submachine guns is sparse, amounting to just entries in the Winchester Museum’s inventory and a faded battered item tag attached to N2. A confusing element is that the inventory simply refers to the two prototypes as N-1 and N-2, with no mention of an N4.
There is also believed to be original engineering drawings housed in the Winchester Archival collection, currently held by the McCracken Research Library, but searches by myself and library staff  have been unable to locate these.

It is unclear if the tag from N2 is contemporary, perhaps added when the gun was handed over to Winchester’s museum, or if it was added later. In under 100 words it give us a short potted history of the N2 itself and the company’s programme to develop a submachine gun.

N2's item tag
Close up of the N2’s item tag detailing the gun & program’s history (Matthew Moss)

Houze suggests the development programme began in 1955 and the tag attached the N2 suggests that development ceased in 1957, whether this is solely for that gun or the entire programme is unclear. This would make Winchester’s weapon a contemporary of the famous Israeli UZI.

The tag describes the N2 as a 9mm blowback ‘NATO Burp Gun’, followed by the name A.A. Arnold, a Winchester engineer perhaps best known for writing a series of manuals for Winchester firearms, followed by ‘dropped Dec ’57’. In his 1994 book, Winchester Repeating Arms Company: Its History & Development from 1865 to 1981, Houze suggests that the weapons were designed by A.A. Arnold and Melvin M. Johnson in 1955, for possible adoption by NATO. The association with NATO might also be the origins of the ‘N’ prefix. I have been unable to find any published patents attributed to Arnold, Johnson or the company relating to the experimental submachine gun.

I contacted NATO’s Archives who advised that they were unable to find any reference or documentation relating to a direct NATO submachine gun requirement. Another possibility is that the weapon was developed to market more broadly to NATO member nations. The submachine gun market at this time in Europe, however, was already saturated by both wartime surplus and a new generation of guns, including the Sterling, the UZI, the Madsen M50, and the Carl Gustav m/45.

N2 prototype
Right side profile view of the N2 ‘in-the-white’ prototype with its stock deployed (Matthew Moss)

The reverse of the N2’s label documents the prototype weapon’s reliability and feeding problems. The tag states that the N2 did “not eject well” and that the bolt slide assembly was too heavy. It also highlights failures to cycle properly with extracted cartridge cases catching under the firing pin. The label then gives a brief description of some of the N2’s features: “fixed firing pin, 33x Mag. Folding stock.” Interestingly, it also notes that the weapon would be cocked by a rod – the hole for which had not yet been added. The tag ends with a suggestion that the heavy one piece bolt assembly should be lightened.

N2 Tape
Close up of the N2’s difficult to decipher tape note (Matthew Moss)

N2 itself also has a piece of masking tape, on the recoil spring assembly cover, with its serial number and calibre written on it, along with A.A. Arnold’s name and some words that are too difficult to make out, but include ‘feed’.

Houze has also suggested that Melvin Johnson, designer of the Johnson rifle and light machine gun who joined Winchester as a designer and adviser in the early 1950s for a short time, and Stefan Janson, designer of the Brtish E.M.2 bullpup and subsequent Winchester engineer, both worked on the project. However, I have been unable to find any documentary evidence of their involvement.

Examining the N2:

N4 and stripped N2
Winchester N4 and disassembled N2 prototype (Matthew Moss)

We can learn a lot from hands on examination of the two Winchester ‘N’ prototypes. Examining N2 we find that the receiver is made up of a piece of shaped sheet metal with a rounded upper half containing the barrel, bolt and cutouts for the grip points on the bolt assembly that allow charging. The bolt assembly rides over the rear portion of the barrel and projects back into the receiver. The lower section of the stamped receiver is rectangular and has a cut out for a separate magazine housing and fire control mechanism consisting of a trigger and push through safety – which we did not remove during disassembly. The N4 is missing its safety.

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Close up of the N2’s magazine housing and trigger guard, note also the trunion freed from the receiver (Matthew Moss)

In the N2, the magazine housing is held in place by the stamped metal trigger guard which rocks into a notch behind the trigger and at the front interfaces with a notch in the magazine housing which has to be placed in the receiver at the same time, both are then held in place by a screw. This was changed in the later ‘N4’ with the trigger guard as a separate independent piece.

Winchester N2 Prototype Reassembly:

The side plates, muzzle end cap and recoil spring assembly cover all made from Aluminium – ostensibly to reduce weight. The submachine gun prototypes both use a pinch cocking method similar to that seen in the earlier British BSA WELGUN developed during WWII. The recoil spring proved to be too strong to cock easily, the addition of ‘rod’ cocking handle is suggested on the N2’s tag. The blued, later N4 prototype, however, is still lacking a conventional cocking handle. The pinch cocking method is not ergonomic, the user’s fingers could easily be caught by reciprocating bolt in charging cut outs in the receiver.

DSC_0053
The N2 prototype disassembled, sadly we were unable to free the bolt from the receiver (Matthew Moss)

Another ergonomic consideration is the Winchester’s submachine gun’s unusually swept back pistol grip angle, the angle of the forward grip made by stock when folded is also similarly angled. Both the weapons have a push though safety selector just above the trigger (likely safe & fully automatic, but could not check as gun unable/difficult to cycle the prototypes easily). The weapon likely fed from a double stack, single feed magazine – either of an similar pattern to the MP40 or proprietary. The N4 seen in Houze’s 1994 book is shown with an MP40 magazine. UZI magazines fit the weapon but don’t lock into place.

The basic design does not change substantially between the prototypes with the control configuration, folding wire stock, pistol grip angle and magazine housing dimensions remaining the same. The N4, however, differs from the earlier prototype in a number of respects. The N4’s nose cap now fits over the rounded half of the receiver, rather than sitting flush and the cut outs in the upper receiver to access the bolt assembly for charging have been moved back slightly.

N4 close up
Right side view of the N4 blued prototype, note the half cocked bolt and the narrower grip serrations on the bolt assembly. Note also the intersection points of the recoil spring assembly cover and the upper receiver (Matthew Moss)

The later N4 model has pins in place of some of the screws used on the N2. The side plates have been replaced by a one-piece recoil spring assembly cover which projects back further over the magazine housing to the rear of the receiver. The most fundamental difference between the two is that it appears that the front part of the N4’s receiver has been significantly altered with the lower receiver at the front of the gun removed. It appears to have been replaced by the recoil spring assembly cover which appears to slot into the receiver. Sadly, we didn’t have time to disassemble the N4 to examine this.

The N4’s bolt assembly also has more serrations, in a slightly different orientation, on its bolt assembly gripping area, but still no charging handle as recommended on the N2’s tag. The ejection port on the blued prototype is also at a position closer to 12 o’clock when compared to the N2s.

Right side 2 Winchester SMG prototypes
Right side profile view of the two prototypes with their stocks deployed (Matthew Moss)

The N2 has a metal trunnion block, that the recoil spring guide rod screws into, this is held in place within the receiver by a cross pin. The bolt appears to be removed through the rear of the receiver once the stock assmbly/end cap is removed and the bolt assembly freed.

The folding stock was retained by spring tension of the wire metal stock against a wingnut-shaped catch that is riveted onto the recoil spring assembly cover. The stock is locked by a spring loaded push button system similar to the MP40s, this is not particularly sturdy. The shape of the wire stock itself is reminiscent of the US M3. When folded the butt of the wire stock acts as a front grip, the retention of the stock is surprisingly strong and stable.

Intriguingly, the Winchester Museum inventory notes that the guns are designated the N-1 and N-2, with an additional wooden model of the ‘Nato Burp Gun’ being transferred along with a box of duplicate parts in steel for the N2’s aluminium parts.

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Specifications:

Calibre: 9x19mm
Action: Blowback
Overall length: ?
Barrel length:  7.5 inches
Weight empty: ?
Magazine capacity: 33 rounds

Bibliography:

Winchester Repeating Arms Company: Its History & Development from 1865 to 1981, H. Houze (1994)


My thanks to the Cody Firearms Museum at the Buffalo Bill Center of the West for allowing me to examine and film the Winchester submachine gun prototypes. Special thanks to the CFM’s assistant curator Danny Michael for helping disassemble the N2.

All photographs taken by Matthew Moss, courtesy of the CFM & the Buffalo Bill Center of the West. Please do not reproduce photographs without permission or credit.

©The Armourer’s Bench 2018

Live Fire: L2A3 Sterling SMG

In this episode we bring you our first live fire and slow motion footage! Matt had the opportunity to fire a British L2A3 Sterling submachine gun and Vic captured some great video. The Sterling was adopted by the British military in 1954 and standardised as the L2A3 in 1956.

Designed by George Patchett, at the Sterling Armaments Company, development began towards the end of the Second World War. After a decade of development and testing the British Army adopted the Sterling. It remained in service into the 1990s and Sterling produced and sold the gun overseas until the company closed in the late 1980s. Licensed versions of the Sterling were made in Canada and production continues today in India.

While the Sterling Armaments Company, the original developers and manufacturer of the gun, produced L2A3s for the government and the commercial market most of the British Army’s Sterlings were made by the government owned Royal Ordnance Factory in Fazakerly near Liverpool.
The gun featured in the video is a Fazakerly-made British Army L2A3, the magazine is also of the slightly simplified government pattern.

slow motion Sterling smg
Frame from the slow motion footage showing a spent 9x19mm case being ejected from the L2A3 (TAB)

In this episode we look at the firing cycle of the L2A3 and how the weapon works. The Sterling uses a standard blowback action and this footage shows it firing in semi-automatic. We can see the breech block travel forward, strip a round from the magazine and chamber it. The round is fired and the breech block then travels rearward again before repeating the cycle.

In future videos we will discuss in-depth the design, development and history of the Sterling.

We would like to thank Graham over at www.slomocamco.com for the loan of the brilliant slow motion camera which captured this great footage!


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AAI Advanced Combat Rifle

This is the first of three introductory videos looking at the US Army’s ACR prototypes. We will be revisiting these later to show disassembly and how they worked. You can check out our introduction to the H&K G11 here. You can also find our in-depth ACR Program overview article here.

The AAI Corporation was founded in 1950, as Aircraft Armaments, Inc., and has long been involved in advanced firearms design, taking part in a number of the US military’s previous small arms programs. Throughout the Cold war AAI was involved in the US Army’s search for a new advanced infantry weapon system. Before we examine the AAI ACR, it is important to understand the context in which it evolved.

The Special Purpose Individual Weapon (SPIW) program, an off-shoot of Project SALVO began in the early 1950s and ran until the late 1960s. During the SPIW program AAI developed a series of designs, including an entire family of weapons, which used flechette technology. These culminated with the XM19 rifle, or SFR – Serial Flechette Rifle.  The XM19 represented the pinnacle of over a decade of flechette technology development, however, the end of the US war in Vietnam saw the need for SPIW disappear and the program was wound down.

4 guns from AAI's family of weapons 60s SPIWs
AAI SPIW family of weapons from the early 1960s (Reproduced in Stevens & Ezell’s SPIW Deadliest Weapon)

In the early 1970s SPIW essentially morphed into the Future Rifle Program, but with the end of US involvement in Vietnam, this also proved a failure. During the early 1980s the US Army awarded development contracts to both AAI and Heckler & Koch to develop caseless ammunition and a weapon system capable of firing it. While H&K G11 is no doubt the better known of the two weapons, AAI’s Caseless Weapon, while a move away from flechette technology, was also an interesting design.

AAI's Caseless Ammunition Rifle (US Army)
AAI’s Caseless Ammunition Rifle, another image available here (US Army)

Firing a variety of ammunition the AAI design was capable of firing a high cyclic rate 3-round burst at 1600-1800rpm. The ACR program summary report noted that the AAI Caseless project was feasible and only lacked development funding to make it a reality, as the design was much simpler than the G11.

AAI were one of six companies to respond to the ACR program’s Request for Proposals, released in September 1985. AAI’s ACR was an evolution of the earlier SFR/XM19 rifle. The weapon AAI submitted was gas-operated, fed from a 30-round box magazine, and fired a brass cased flechette round in either single shot or a high cyclic rate three round bust – fired at a cyclic rate of ~1800rpm.

Left of the AAI ACR rifle (Matthew Moss)
Left-side view of AAI Corporation’s ACR entry (Matthew Moss)
AAI Corp ACR rifle (Matthew Moss)
Right-side view of AAI’s ACR entry (Matthew Moss)

AAI’s ACR fired from a closed bolt and used a muzzle device to reduce muzzle climb during burst firing. The 1990 ACR Program Summary report explains how the rifle’s gas system worked:

“…incorporate an ‘entrapped gas’ operating system. Gun gases enter a cylinder, drive a piston to power the system, and prevent any leakage of propellant gases and residues into the other mechanism parts.”

AAI developed a polymer saboted steel 10.2 gr ‘sub-calibre’ flechette which fitted within a standard M855 brass case. As a result the rifle used a proprietary magazine to avoid the accidental chambering of conventional 5.56x45mm rounds. The flechette rounds had a muzzle velocity of 4,600 ft/s with propellant produced by the Olin Corporation.

DSC_0146
An AAI Corporation ACR marked serial number 20 (Matthew Moss)

The rifle was designed to mount a quick detachable 4x optic and also had a white-highlighted shotgun-style rib sight along the barrel to aid snap shooting. The rifle was one of the longest entries with an overall length of 40 inches or 101.6cm. Interestingly, rather than a push-button magazine release, AAI opted for a large paddle release.

Front end of AAI ACR (Matthew Moss)
The fore-end of the AAI ACR, note the front sight post and muzzle device which reduced muzzle climb during burst firing (Matthew Moss)

AAI’s rifle borrowed some of its external ergonomic characteristics from the M16A2, then in service. With a moulded polymer pistol grip and butt, forming part of the lower receiver, shaped to mimic the M16’s. It also utilised the M16’s sling loops and butt plate.

According to the ACR program summary the AAI entry proved to be a “mature design which performed in a reliable fashion” during the field trials. It was regarded as a weapon with known reliability with a flechette round superior to the Steyr, the other flechette-based entry.

AAI ACR Ejection Port (Matthew Moss)
Close up of the right-side of the AAI ACR, note the ejection port and moulded plastic case deflector, selector level, paddle magazine release and sight mount (Matthew Moss)

Today, AAI continue to develop both small arms and other defence technologies. Now a part of Textron, they are currently involved in the US Army’s Lightweight Small Arms Technologies (LSAT) program.

If you enjoyed the video and this article please consider supporting our work here.


Specifications (From 1990 ACR Program Summary):

Length: 40 inches / 101.6cm
Weight: 9.39 lbs / 4.26kg
Sights: Iron or 4x optic
Action: Gas operated
Calibre: 5.56mm brass cased flechette
Feed: 30-round box magazine

You can find out overview article on the ACR program and all of the rifle here.


Bibliography:

Advanced Combat Rifle, Program Summary, Vol.1, ARDEC, 1992 (source)

‘Revisiting the SPIW Pt. 1-3’, Small Arms Review, R. Blake Stevens, (123)

The SPIW The Deadliest Weapon that Never Was, R. Blake Stevens & E.C. Ezell (1985)

Our thanks to the collection that holds these wonderful examples of the ACR rifles


Please do not reproduce photographs taken by Matthew Moss without permission or credit. ©The Armourer’s Bench 2018.