Apparatus and methods are described for a weapon simulator. An example weapon simulator includes a pressure piston, which is couplable to a weapon, which acts to open a breech, and which is seated in a pressure cylinder. An example pressure piston includes a slider. The slider holds a pressure intake opening open and keeps one or more pressure outlet openings closed when the breech is in a front-most position. In addition, the slider keeps the pressure intake opening closed and holds the one or more pressure outlet opening open when the breech is in a rear-most position.