JaTiMatic
Encyclopedia
The Jatimatic is a Finnish
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

 9 mm
9 mm caliber
This article lists firearm cartridges which have a bullet in the caliber range. The most prevalent of these rounds is the 9x19mm Parabellum.*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge....

 submachine gun
Submachine gun
A submachine gun is an automatic carbine, designed to fire pistol cartridges. It combines the automatic fire of a machine gun with the cartridge of a pistol. The submachine gun was invented during World War I , but the apex of its use was during World War II when millions of the weapon type were...

 developed in the late 1970s and early 1980s by Jali Timari. The submachine gun made its debut in 1983. The Jatimatic was manufactured in very limited numbers (approx. 400) initially by Tampereen Asepaja Oy of Tampere
Tampere
Tampere is a city in southern Finland. It is the most populous inland city in any of the Nordic countries. The city has a population of , growing to approximately 300,000 people in the conurbation and over 340,000 in the metropolitan area. Tampere is the third most-populous municipality in...

 and later—Oy Golden Gun Ltd (as the GG-95 PDW, re-introduced unsuccessfully in 1995). The firearm was designed primarily for police, security forces and armored vehicle crews. It was never adopted into service by the Finnish Defence Forces
Finnish Defence Forces
The Finnish Defence Forces are responsible for the defence of Finland. It is a cadre army of 15,000, of which 8,900 are professional soldiers , extended with conscripts and reservists such that the standard readiness strength is 34,700 people in uniform...

, although the later GG-95 PDW version was tested by the FDF in the 1990s; the conclusion of the tests was that the GG-95 was not suitable as a service weapon.

Operating mechanism

The Jatimatic is an automatic, open bolt
Open bolt
A semi or full automatic firearm is said to fire from an open bolt if, when ready to fire, the bolt and working parts are held to the rear. When the trigger is pulled the bolt goes forward, feeding a round from the magazine into the chamber and firing it...

, blowback
Blowback (arms)
Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gases created by the ignition of the propellant charge....

-operated firearm. A unique feature of this design is the angle of the bolt
Bolt (firearm)
A bolt is a mechanical part of a firearm that blocks the rear of the chamber while the propellant burns.In manually-operated firearms, such as bolt-action, lever-action, and pump-action rifles and shotguns, the bolt is held fixed by its locking lugs during firing, forcing all the expanding gas...

 guide rails in relation to the bore axis. When fired, the telescopic bolt
Telescoping bolt
A weapon with a telescoping bolt is one with a bolt which telescopes over, that is, wraps around and past, the breech end of the barrel...

 which encloses the barrel for most of its length, recoils up an inclined plane at a 7° angle to the barrel, giving an element of braking to the bolt, and also resisting the upward movement of the barrel during fully automatic fire. This arrangement aligns the shooters hand wrapping the pistol grip
Pistol grip
On a firearm or other tool, the pistol grip is that portion of the mechanism that is held by the hand and orients the hand in a forward, vertical orientation, similar to the position one would take with a conventional pistol such as the M1911....

 directly with the longitudinal axis of the barrel. The pistol grip is also located higher than on many other submachine guns, causing recoil to be directed backwards to the user rather than upwards, eliminating muzzle climb
Muzzle climb
Muzzle climb refers to the elevation of muzzle of automatic and rapid-fire semi-automatic firearms caused by combined recoil from multiple shots being fired in quick succession....

 and making the weapon more controllable when being fired one-handed.

Features

The casing extractor is contained in the bolt while a fixed ejector is installed in the trigger housing. Due to the upward angle that the bolt must traverse in order to fire, the weapon has no feed ramp, so bullets are pushed by the bolt directly from the magazine into the chamber.

The weapon's ejection port is covered in both the forward (closed) and retracted positions of the bolt assembly, protecting the gun's internal mechanisms from dust and debris. The left exterior surface of the bolt is engraved with a visual warning sign labeled "FIRE", which is visible through the ejection port when the weapon is cocked (the bolt is moved to the rear position).

The firing mechanism features a two-stage progressive trigger
Progressive trigger
A progressive trigger is a trigger that allows different firing rates based on how far it is depressed. For example, when pulled lightly, the weapon will fire a single shot. When depressed further, the weapon fires at a fully automatic rate....

 that provides two modes of operation: semi-automatic fire, when the trigger is squeezed momentarily, and fully automatic fire—produced when the trigger is pulled all the way through and held back. No fire control selector is provided. The Jatimatic features a striker firing mechanism with a fixed firing pin installed inside the bolt (the dual-purpose return spring also serves as the firing pin spring).

Many of the weapon's parts, including the frame, pistol grip/charging handle, trigger, sear, and disconnector are made of plastic, while many other parts are made of stainless steel; altogether, it has only 39 individual components. The receiver
Receiver (firearms)
In firearms terminology, the receiver is the part of a firearm that houses the operating parts. The receiver usually contains the bolt carrier group, trigger group, and magazine port. In most handguns, the receiver, or frame, holds the magazine well or rotary magazine as well as the trigger mechanism...

 is made from stamped
Stamping (metalworking)
Stamping includes a variety of sheet-metal forming manufacturing processes, such as punching using a machine press or stamping press, blanking, embossing, bending, flanging, and coining. This could be a single stage operation where every stroke of the press produce the desired form on the sheet...

 sheet steel
Sheet metal
Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking, and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of the material...

 with a hinged cover.

The Jatimatic lacks a folding stock
Stock (firearm)
A stock, also known as a buttstock or shoulder stock, is a part of a rifle or other firearm, to which the barrel and firing mechanism are attached, that is held against one's shoulder when firing the gun. Stocks are also found on crossbows though a crossbow stock is more properly referred to as a...

 common for this class of firearm; the weapon is instead fired unsupported from the hip or raised arm, without resting the firearm on the shooter's shoulder. However, aftermarket stocks are available which fasten to the lower side of the pistol grip and give it much greater accuracy, while also protecting the rear sight from being bent or broken.

Feeding

The submachine gun uses 20 or 40-round detachable box magazines
Magazine (firearm)
A magazine is an ammunition storage and feeding device within or attached to a repeating firearm. Magazines may be integral to the firearm or removable . The magazine functions by moving the cartridges stored in the magazine into a position where they may be loaded into the chamber by the action...

, made of extruded aluminum with a plastic follower and a steel spring and floor plate. The weapon can also accommodate magazines designed for the Swedish K
Carl Gustav M/45
Kulsprutepistol m/45 , also known as the Carl Gustav M/45 and the Swedish K SMG, is a 9 mm Swedish submachine gun designed by Gunnar Johnsson, adopted in 1945 , and manufactured at the Carl Gustafs Stads Gevärsfaktori in Eskilstuna, Sweden. The m/45 was the standard submachine gun of the...

 and, with some modifications, the Smith & Wesson M76
Smith & Wesson M76
The Smith & Wesson M76 submachine gun was produced by Smith & Wesson from 1967 to 1974. It is a clone of the Carl Gustav M/45.-History:In 1966, the Swedish government blocked the sale of firearms to the United States because it opposed the Vietnam War...

. The weapon is chambered for the NATO-standard 9x19mm Parabellum pistol cartridge
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...

.

Reloading the weapon involves charging the folding vertical forward grip
Vertical forward grip
A vertical forward grip is a vertical grip that is designed to attach to a firearm for the forward hand . These aid in the maneuverability of the firearm, since the natural angle of a persons outstretched hand is more oriented to grasping objects at a vertical angle, rather than a horizontal one...

, which is simultaneously the cocking handle
Cocking handle
The cocking handle is a device on a firearm which, when operated, results in the hammer or striker being cocked or moved to the ready position...

. The grip is deployed and locked forward with a spring latch and then charged to the rear and guided back forward in order to chamber a round. The forward grip does not reciprocate with the bolt during firing and also acts as a safety mechanism
Safety (firearms)
In firearms, a safety or safety catch is a mechanism used to help prevent the accidental discharge of a firearm, helping to ensure safer handling....

in the stowed (folded) position, immobilizing the bolt in either its forward or rear positions by using a lug on the grip to engage and recess into a notch in the bolt. This allows the weapon to be carried safely either loaded or unloaded and provides a drop safety feature.
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