O Ring
A ring of rubber or urethane that acts as a seal. You would be surprised how many faulty markers are miraculously cured by simply changing the o-rings.

Open Bolt
The opposite of a closed bolt gun as described above. Examples include the Automag, Spyder, Prolite and Armson.

Paintball
Spherical gelatine encapsulated paint shot from markers for fun and eaten by psychos at Paintball tournaments.

Paintball God
Anyone who makes it onto PGI's top 100 players as well as David Jarvis, who remains overlooked as a result of an evil imperialist plot to undermine the third world at the expense of the illuminati and the capitalist running dogs with their free-mason and alien allies.

PGI
(see also Paintball Games International, The Bible, The Greatest Story Ever Told, Penthouse). The world’s finest Paintball magazine, PGI is produced by a God-like race of highly evolved people who dedicate their lives to the betterment of the sport. PGI is also a by-word for ‘cool’, ‘phat’ ‘dope’, ‘hip’ and ‘groovy’: i.e. ‘Man, that tune was PGI,’ or, ‘That chick is soooo PGI, dude,’

Porting
Symmetrically placed holes in a barrel that quieten the marker when it is shot and provide a smoother flight for the paintball by allowing excess gas to blow off.

Pounds per Square Inch (PSI)
The EU will never get Paintball to go metric. PSI is the most widely used Paintball measurement for pressure.

Powerfeed
A ball feed system on open bolt markers that has an opening to prevent bounce-back of paintballs. It works by allowing excess gas to be expelled.

Pull-Thru
A device for cleaning burst paintballs from out of a barrel.
Pump Action: A marker that needs to be manually re-cocked before it can be shot.