Breechloader

A breechloader^[1][2] 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 breech-loaders, while firearms made before the mid-19th century were mostly smoothbore muzzle-loaders. Only a few muzzleloading weapons, such as mortars, rifle grenades, some rocket launchers, such as the Panzerfaust 3 and RPG-7, and the GP series grenade launchers, have remained in common usage in modern military 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 the 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.