Different from semi-automatic or full-automatic guns with automatic ammunition supply, bolt-type guns are also called manual ammunition supply guns, which refer to guns that require the shooter to apply force completely by hand to complete the process of sending bullets into the chamber and taking out the spent shells from the chamber after shooting.
Because bullets are loaded and unloaded manually every time, the firing rate of such firearms is much lower than that of semi-automatic or full-automatic firearms that automatically replenish ammunition.
However, compared with the firearms with automatic ammunition supply, the internal ballistics of manual firearms are not affected by the automatic re-entry bolt, the chamber pressure is easier to maintain stability, and its firing accuracy has great advantages, so it is more popular when there is no requirement for firing rate.
The bolt operated by the bolt first appeared on the firing pin rifle of M 184 1 Dreiser, and was later adopted by the French M 1866 Xiasaibo rifle. 1867 On the eve of the Franco-Prussian War, Mao Se brothers developed a rotary bolt-drawing machine with metal shell bullets, and obtained a patent in 1868.
There are three mainstream rifles with bolts, the earliest Mao Se, the later Li En Field and Mohin Nagan. Their principles are all based on rotary locking, and the difference lies in the structure and operation mode of the locking mechanism, that is, the lock tongue and the watch case.
Li Enchang adopts the locking tenon in the middle of the bolt. When unlocking, the rotation angle of the bolt handle is at least 60 degrees, which is labor-saving and easy to wear and there is a risk of accidents. Mosinnagan's locking mechanism uses both the locking tenon of the bolt and the locking groove of the barrel socket. When unlocking, the rotation angle of the bolt handle is 90 degrees like that of Mao Se, so it requires more force and is the safest.
In fact, the latch locking tenon or the cylindrical socket locking groove or both are used at the same time. Mao Se rotary bolt machine has original barrel socket locking slot, which is used by Mao Se 187 1 rifle, and Gew 98 rifle is locked by the lock tenon of gun head. The latter is the most common bolt design in the world, which is widely promoted in various countries.