ROF (Rate of Fire) Also referred to as “RPM”, or Rounds Per Minute. The rate of fire refers to the measure of shots that can be fired by a gun in one second or one minute in its fully automatic mode. Airsoft Automatic Electric Guns (AEGs) usually have an ROF of about 700rpm. There are some Airsoft Gas Blow-Back guns (GBBs) which can shoot at an astonishing 1,000rpm.

Round A term used in referring to a real bullet or BB. This term was derived from the shape of a traditional bullet, which is round. Round also refers to the number of bullets that a magazine can hold, such as a 100 round mag.

RPM (Rounds Per Minute) The rate of fire measured in rounds per minute. Please also see ROF.

RSAF (Royal Small Arms Factory, UK) A UK government owned rifle factory which has manufactured British military weapons since 1804.

Safety Switch When engaged in the on position, the safety switch will not allow guns to be fired. All firearms both real and replica should be stored with the safety catch on.

SAS (Special Air Service) An elite commando force of the British Army, they are some of the best trained soldiers in the Western World. Formed in 1941, this force is noted for its secret and vital tactical work behind enemy lines. Some Airsoft guns can be found with the term SAS attached to them.

SAW (Squad Automatic Weapon) Please see light or general purpose machine gun.

SD (Schall Daempfer) German for “Sound Suppressor”. These integrated suppressors on guns are more commonly known as silencers. Models that have these silencers have the letters SD after their reference name, such as the H&K MP5-SE.