In a cellular automaton, a gun is a pattern of which the main part repeats periodically, like an oscillator and which also periodically emits spaceships. There are then two periods that may be considered. There is the period of the spaceship output and the period of the gun itself, which is necessarily a multiple of the spaceship output's period. A gun whose period is larger than the period of the output is a pseudoperiod gun. In the Game of Life, it is possible to construct a glider gun with the gliders having every period greater than or equal to 14.
The smallest gun found so far in Conway's Game of Life is the Gosper Glider Gun
