Type 42 submachine gun

Type 42 submachine gun
File:Type 42 SMG.png Type 42 with stock extended and folded, and a field-stripped example. Type 39 for comparison.
Type	submachine gun
Place of origin	Menghe
Service history
In service	1942–1970s
Wars	Pan-Septentrion War Menghean War of Liberation
Production history
Designer	Insŏng Arsenal
Designed	1941-1942
Manufacturer	numerous
Produced	1942-1945
Specifications
Weight	2.85 kg (6.28 lb)
Length	stock extended: 812mm stock folded: 596mm
Barrel length	274mm
Cartridge	7.5×25mm Menghean
Action	blowback, open bolt
Rate of fire	900 rounds per minute
Muzzle velocity	500 m/s
Effective firing range	200m
Feed system	40-round magazine
Sights	Iron sights

The Type 42 submachine gun or Type 42 machine pistol (Menghean: 42식 기관단총 / 四二式機關短銃, sal-i-sik gigwandanchong) is a submachine gun developed in the Greater Menghean Empire during the Pan-Septentrion War. It is notable for being built entirely out of stamped metal components, making it quick and inexpensive to manufacture. The Type 42 was developed as an improvement on the Type 39 submachine gun, but never fully replaced it, and both remained in production until Menghe's surrender in 1945.

Development

Menghe's first domestically designed and widely produced submachine gun was the Type 39, which was developed during the early war in response to the appearance of KP/-31 Rajamaa SMGs among foreign volunteers in Themiclesia. Overall, the Type 39 was a decent design, relatively easy to manufacture and very easy to maintain. Yet operational experience in the urban battles of 1940 and 1941 raised some concerns about the weapon, and in the middle of 1941 the Imperial Menghean Army began searching for a replacement.

Ha Dong-u, now the lead engineer at the Insŏng Arsenal, was the first to take up the challenge. While his design team was busy modifying and simplifying the Type 39 to produce a new variant, Ha decided to start from scratch for the new model. His goal, in the spirit of Jŏng Sŭng-yong's past work, was to produce a weapon which was simultaneously easy to produce and durable in the field. Part of his approach was to use as many stamped parts as possible, in contrast to the Type 39, which was built around a milled receiver. He also aimed to address a number of complaints from the field about the Type 39, which included its non-sealed receiver, its poor safety, and its all-around bulkiness.

The resulting prototype was submitted for Army evaluation in the spring of 1942, and approved for production before June, but Ha Dong-u was not fully satisfied with its performance on trials and pleaded for another two months to fine-tune the design. The procurement office relented, and Ha revised the design accordingly, submitting a second prototype for evaluation in August. It was promptly accepted for service as the Type 42.

Design

The Type 42 fires from an open bolt using a simple blowback action and a fixed firing pin, though the resemblance to the Type 39 before it ends there. The charging handle is non-reciprocating: the operator pulls it back to cock the weapon, but after it's pushed forward manually or by the bolt, it remains in the forward position. Inside the receiver, the charging has a thin steel dust cover extending back parallel to the bolt, ensuring that while it's in the forward position no dust or mud can enter the receiver. The initial prototype had another dust cover over the magazine well, but this was removed in the July revisions.

While both the Type 42 and Type 39 fire the same 7.5×25mm cartridge from curved 40-round box magazines, the magazines are actually not interchangeable. Type 42 magazines are double-stack, double-feed, making them easier to load in the field without special equipment. They also feature a metal band wrapped in a "U" shape about 2/3 of the way to the top, which prevent them from being inserted too far into the magazine well and presumably aid in identification. The magazine release button is located on the back of the magazine well and protected on either side by a thin metal "wing" to prevent accidental release.

In order to make the weapon more compact for urban combat, Ha Dong-u included a pistol grip and folding skeleton stock from the first variant onward, replacing the wooden furniture on the Type 39. The folding stock on the Type 42 ends in a curved "A" shape, linking on top and crossed by a pin in the middle but open at the bottom. This allows it to be folded forward under the receiver even when a magazine is inserted.

The iron sights on the Type 42 are relatively simple, consisting of a rear L-shaped piece which can be flipped to three range settings, this time set at 50 meters (first panel aperture), 100 meters (second panel aperture), and 200 meters (second panel v-notch). The front sight is hooded with a central post. Rate of fire is fairly high at around 900 rounds per minute, the result of a lighter bolt and a shorter recoil spring; while the Type 42 retains two notches cut across the top of the barrel as a compensator, its higher rate of fire, lighter weight, and skeleton stock make it more difficult to control. This is somewhat worsened by the fact that as on the Type 30, there is no semi-automatic fire setting, only safe and full auto.

In contrast to the Type 39, there is no "notch safety" for the charging handle, but instead a conventional safety pin above the trigger: when this is pushed from left to right, it locks the trigger in place if the weapon is cocked. In some ways this is a step backward from the Type 39, especially its later variants, as there is no safety mechanism preventing the bolt from bouncing back and chambering a round if the weapon is dropped with the bolt forward.

In accordance with Ha Dong-u's aims, the Type 42 is made almost entirely from stamped sheet metal, though many parts are better described as pressed; the final geometry is relatively simple. Only the barrel and bolt are made from milled components. The construction also makes extensive use of spot welds in place of machine screws, and includes no threaded metal components. Surviving documents claim that the Type 42 took only 2.9 hours of machining to manufacture at a well-tooled facility, a major reduction over the Type 39.

Disassembly is also very straightforward. With the bolt forward, the operator depresses a button on the end of the upper receiver, which is normally held in place by the tension on the recoil spring, a solution later found on FSR-made AK-series rifles. On the Type 42, this allows the upper and lower receiver to pivot apart on a pin just forward of the magazine well. Depressing the button again allows the operator to unhook the spring and remove it, followed by the bolt; once the bolt is removed, the charging handle and its dust cover come loose and can be removed from inside the upper receiver.

Service

The Type 42 first arrived in front-line units at the end of 1942, at which point the Imperial Menghean Army was in full retreat. It earned a mixed reputation in Menghean records; while lighter than its predecessor, and sporting a higher rate of fire, it was also a little more fragile, partly because of the conditions under which it was built. It lacked the smooth and generally controllable fire of the Type 39, and while preferable in close-quarters combat, it was less useful on open terrain.

While the Type 42 was optimized for easy manufacture, it never fully replaced the Type 39 on the production lines. Instead, the procurement office tasked new arms factories with building the Type 42 while leaving Type 39 factories in operation. Part of the reasoning behind this stemmed from path dependency; existing factories were already producing Type 39s at maximum output, and because the Type 42 was of predominantly stamped construction, retooling factories to produce it would take scarce time and resources. The stamping or pressing operations required by the Type 42 also made it hard to produce in small workshops with lathes and casting, a quality that Menghean war planners found increasingly desirable toward the end of the conflict.

Nevertheless, there were some simplifying operations over the course of the Type 42's production. Over the course of 1944, most factories were retooled to produce a simplified version with a wooden pistol grip rather than a stamped steel one, and many factories omitted the charging handle metal dust cover. The quality of manufacture in general declined as the war went on, though not to the same degree as on other Menghean firearms, as the Type 42 still required stamping or pressing machinery and was not as well-suited to small workshops.

See also

• Type 39 submachine gun
• Type 17 rifle
• Type 41 self-loading rifle
• Type 32 light machine gun