A breechloader is a firearm, in which the user loads the ammunition from the breech end of the barrel (i.e., from the rearward, open end of the gun's barrel), as opposed to a muzzleloader, in which the user loads the ammunition from the (muzzle) end of the barrel.
The vast majority of modern firearms are generally rifled breech-loaders, while firearms made before the mid-19th century, were entirely made up of smoothbore muzzle-loaders. With a few exceptions, such as mortars, rifle grenades, some rocket launchers, such as the Panzerfaust 3 and RPG-7, and the GP series grenade launchers, are the only muzzleloading weapons that have remained in common usage during modern conflicts. However, referring to a weapon specifically as breech loading is mostly limited to non-repeating firearms, including single-shots, derringers, double-barreled shotguns, double-barreled rifles, combination guns, and volley guns.
Breech-loading provides the advantage of reduced reloading time, because it is far quicker to load the projectile and propellant into the chamber of a gun or cannon than to reach all the way over to the front end to load ammunition and then push them back down a long tube – especially when the projectile fits tightly and the tube has spiral ridges from rifling. In field artillery, the advantages were similar – crews no longer had to get in front of the gun and pack ammunition in the barrel with a ramrod, and the shot could now tightly fit the bore, greatly increasing its power, range, and accuracy. It also made it easier to load a previously fired weapon with a fouled barrel. Gun turrets and emplacements for breechloaders can be smaller, since crews don't need to retract the gun for loading into the muzzle end. Unloading a breechloader is much easier as well, as the ammunition can be unloaded from the breech end and is often doable by hand; unloading muzzle loaders requires drilling into the projectile to drag it out through whole length of the barrel, and in some cases the guns are simply fired to facilitate unloading process.
After breech-loading became common, it also became common practice to fit counter-recoil systems, such as the hydro-pneumatic recoil mechanism on the Canon de 75 modèle 1897, onto field guns and howitzers to prevent the recoil from rolling the carriage back and forth with every shot and ruining the aim. This provided faster rates of fire, but this is not directly related to whether the gun is breech-loading or not. Now that guns were able to fire without the entire carriage recoiling, the crew was able to remain grouped closely around the gun, ready to load and put final touches on the aim, prior to firing the next shot. That led to the development of an armored shield fitted to the carriage of the gun, to help shield the crew from long range area or sniper fire from the new, high-velocity, long-range rifles, or even machine guns.
History
Although breech-loading firearms were developed as far back as the early 14th century in Burgundy and various other parts of Europe, breech-loading became more successful with improvements in precision engineering and machining in the 19th century.
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 in the mid-19th century. For firearms too large to use cartridges, the problem was solved by the development of the interrupted screw.
Swivel guns
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, 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.
Firearms
Breech-loading firearms are known from the 16th century. Henry VIII possessed one, which he apparently used as a hunting gun to shoot birds. Meanwhile, in China, an early form of breech-loading musket, known as the Che Dian Chong, was known to have been created in the second half of the 16th century for the Ming dynasty's arsenals. Like all early breech-loading fireams, gas leakage was a limitation and danger present in the weapon's mechanism.
More breech-loading firearms were made in the early 18th century. One such gun known to have belonged to Philip V of Spain, and was manufactured circa 1715, probably in Madrid. It came with a ready-to load reusable cartridge.