Bolt Action This is a type of a reloading action for single shot and manual reloads. Bolt Action is usually found in accurate long range Airsoft sniper rifles. In reloading the bolt action rifle after a shot, the bolt is pulled back manually by the shooter in order to remove the old bullet case. The bolt is then pushed forward again by the shooter who then loads a fresh bullet into the breach.

Breech The place inside the gun, which houses the bullet/BB at the point of firing. The breech is usually a solid object containing a hole cut out and fitted in line with the barrel, which holds the BB. The BB sits inside the breech until the firing pin/piston fires the gun. The BB then travels out of the front of the breech into the barrel and out through the muzzle of the gun.

Breech Block Houses the breach.

Bullpup The name given to a design of rifle which is characterized by having the magazine and firing mechanism set behind the trigger and grip, instead of the more traditional design where the magazine is in front of the grip. Popular “Bullpup” rifles include such Airsoft replicas as the AUG and the British SA80. The Bullpup design rifle results in a much longer barrel that does not necessarily increase the length of the gun. This increases accuracy without making the gun awkward to handle.

Bump Bump is the Airsoft term for “Ambush”. If an enemy force is bumped, they are caught in a surprise attack.

Bushings Functions like a bearing but with no moving parts. Most Airsoft AEGs are equipped with nylon bushings that hold the axle for each gear in the gearbox. The bushing allows the gear to turn without moving out of position. For premium performance it is recommended that the bushings be replaced with bearings in most AEGs.