Breech-loading gun

A breech-loading gun is a firearm in which the cartridge or shell is inserted or loaded into a chamber integral to the rear portion of a barrel.

Modern mass production firearms are breech-loading (though mortars are generally muzzle-loaded). Early firearms, on the other hand, were almost entirely muzzle-loading. The main advantage of breech-loading is a reduction in reloading time—it is much quicker to load the projectile and the charge into the breech of a gun or cannon than to try to force them down a long tube, especially when the tube has spiral ridges from rifling. In field artillery, breech loading allows the crew to reload the gun without exposing themselves to enemy fire or repositioning the piece (as was required for muzzle-loaded guns) and allows turrets and emplacements to be smaller (since breech loaded guns do not need to be retracted for loading).

Although breech-loading firearms were developed as far back as the late 14th century in Burgundy, breech-loading became more successful with improvements in precision engineering and machining in the 19th century (see Dreyse needle gun).

The main challenge for developers of breech-loading firearms was sealing the breech. This was eventually solved for smaller firearms by the development of the self-contained metallic cartridge. For firearms too large to use cartridges, the problem was solved by the development of the interrupted screw.

Breech-loading swivel guns were invented in the 14th century. They were a particular type of swivel gun, and consisted in a small breech-loading cannon equipped with a swivel for easy rotation, and which could be loaded by inserting a mug-shaped chamber already filled with powder and projectiles. The breech-loading swivel gun had a high rate of fire, and was especially effective in anti-personnel roles.

...
Wikipedia