Firing weapon
When firing a weapon , the breech is in its rear position before the trigger is operated . Only when the trigger is actuated does the bolt snap forward, insert a cartridge from the magazine into the chamber (“the chamber is closed”) and ignite it. A firing weapon tends to tear the line of sight more easily because of the moving mass of the breech before the shot is fired and is therefore usually less precise than a firing weapon . Firing weapons have a higher rate of fire than comparable shooting weapons, since the firing pin - z. B. by the hammer - is operated separately.
Application examples
Early submachine guns with bulk locks are particularly popular . Examples are all the submachine guns used in the First and Second World Wars and the later Uzi .
Most of the machine guns of the Second World War, the German MG 34 , the MG 42 (including the further development MG3 ), the English Bren LMG , the French MAC-24/29 , the Czech ZB vz. 26 , the American Browning Automatic Rifle and others are guns that can be fired, as the forward bolt movement has little effect on the accuracy of guns on the mount or front support. It was more important to avoid spontaneous combustion and to let the barrel cool down a little faster during breaks in the fire.
Advantages and disadvantages
Advantages of closed fire systems:
- Avoiding auto-ignition, cooling the chamber and barrel
- An essential aspect is the cooling of the weapon. Since just a few shots are enough to generate very high temperatures in the weapon, machine guns and machine guns that are designed for sustained fire often use the closing design. This creates more air between the bursts of fire, which cools the system. In addition, there is no cartridge in the hot cartridge chamber between two bursts of fire, which can lead to auto-ignition from overheated cartridges, as with guns firing at the gun . Jamming of the heated cartridge due to thermal expansion is also avoided.
- Simpler structure
- Since a bolt lock is not necessary with relatively weak pistol cartridges (because the inertia of the bolt mass is sufficient to delay the opening of the chamber until the pressure drops in the barrel), the system of a submachine gun can be kept simpler. Since the lock is also an element subject to high mechanical loads, so-called ground locks are more reliable and have a longer service life. In addition, the firing pin is often integrated in the breech of weapons that are being fired, so that a separate firing pin is not required. Since the cartridge is ignited by the impact of the firing pin integrated in the breech into the primer cap , guns to be fired also do not require a striker spring to drive the firing pin or a separate hammer with associated spring.
- State of charge
- The charging status is easier to see thanks to the open lock. It is also advantageous that only the magazine or the belts have to be removed for unloading.
Disadvantages of automatic weapons to shoot, u. a .:
- precision
- While with a firing weapon only the very light trigger mechanism is moved over a short distance before the shot is triggered (a firing pin or a hammer that strikes the firing pin), in the firing mode the massive bolt moves through the entire loading distance the system case before the cartridge is ignited. This movement of a relatively large mass over a relatively large distance can lead to the line of sight breaking before the shot is triggered or the projectile leaves the barrel. This effect may seem minimal, but tearing the muzzle by a fraction of a millimeter already makes a safe hit at 100 m impossible. This problem is negligible for weapons that are mounted on a mount .
- Handling safety
- A major disadvantage is the lack of security when shooting weapons. If the weapon receives a push, a shot can easily be released when the bolt releases from its locking mechanism. This has resulted in many accidents. The Israeli Uzi -Maschinenpistole was after some time because of this with an additional grip safety features.
- Sensitivity to dirt
- Dirt can also easily penetrate the weapon through the open breech, so that it can no longer be fired or it jams. Therefore, shooting weapons must always be specially protected from dirt, rain, etc., which is often difficult on the battlefield.
Advance ignition
When automatic weapons with pre-ignition are to be fired, the cartridge is ignited shortly before the breech or system hits the stop. The use of the kinetic energy of the advancing bolt allows it to be made lighter ( MG FF ), and the weapon shakes less when firing ( Lmg 25 ).
Special case combination weapon
One of the few exceptional hand-held weapons that have both modes, both shooting and shooting , is the German multi - purpose self-loading rifle Fallschirmjägergewehr 42 (FG 42). In the case of continuous fire it is closed (cooling / avoidance of heat ignitions ); in single fire mode it is shooting (precision). Another combination weapon that combines both breech types is the American Johnson M1941 , a light machine gun of about the same age.
literature
- Karl Sellier, Beat P. Kneubuehl : Wound ballistics and their ballistic basics. 2nd completely revised and expanded edition. Springer, Berlin a. a. 2001, ISBN 3-540-66604-4 , p. 113.
Individual evidence
- ↑ Chris McNab : Hand Weapons - A Historical Overview . Neuer Kaiser, 2017, ISBN 978-3-8468-2202-9 , pp. 104 .