.177 - Air gun calibre in inches, equal to 4.5mm.
.22 - Air gun and firearm calibre in inches, equal to 5.5mm.
BB - A type of ammunition normally used in air guns with smoothbore barrels, round plastic or steel balls.
CO2 - Carbon dioxide, a gas propellant used in air guns.
Calibre - Internal diameter of a barrel.
Crip - Short for cripple or crippled, used by some disabled people to describe themselves.
FAC - Fire Arms Certificate.
LR - Long rifle, normally used in conjunction with a calibre such as .22
mil - 1/6400 of a circle, subtends to 1/1000 or one metre at 1000metres
MOA - Minutes of angle, 1 MOA equates to 1 inch at 100 yards, 10ish inches at 1000 yards.
PCP - Pre Charged Pneumatic, an air gun that uses a tank of compressed air for propellant.
Pellet - A type of ammunition, normally made of lead and used in air guns with rifled barrels.
Propellant - A gas, or chemical that is ignited to produce gas, that propels a bullet or pellet.
RFD - Registered Firearms Dealer.
