A slamfire is a discharge of a firearm occurring as a cartridge is being loaded into the chamber. Some firearms are designed to slamfire, but the term also describes a malfunction of self-loading firearms. Shooters accustomed to firearms requiring trigger activation for discharge may be unprepared for a slamfire discharge. Some military firearms are designed to fire from an open bolt condition to avoid unintended discharge of a chambered cartridge cooking off in a gun barrel heated by firing previous cartridges. Activating the trigger of such firearms releases the spring-loaded bolt to move forward stripping a cartridge from the magazine into the chamber. The firing pin impacts the primer as the cartridge is chambered, and the energy released by the discharging cartridge returns the bolt into an open position while ejecting the empty case. Unintentional slamfire More conventional self-loading firearms begin this cycle with a cartridge already in the chamber and await activation of the trigger to allow the firing pin to impact the primer, causing discharge and loading another cartridge into the chamber. The first cartridge must be loaded from the magazine by manually pulling back and then releasing the spring-loaded bolt to chamber the cartridge; and unintentional slamfires may occur if the firing pin activates the primer as the first cartridge is being chambered. Unintentional slamfires may also occur during the normal self-loading process following an intended discharge. Control of firing pin movement is the essential difference between cartridge discharge as the bolt closes, or discharge when the trigger is pulled. Firearms designed to discharge as the bolt closes may have a fixed firing pin or a firing pin which moves forward by inertia as forward motion of the bolt ceases when the cartridge is fully chambered, while more conventional firearms are designed to prevent the firing pin from impacting the primer until the trigger is pulled. Some unintentional slamfires are caused by firing pin malfunction, while others may be attributed to defective cartridges with improperly positioned or unexpectedly sensitive primers. Possible causes Firing pins intended to be activated by a trigger are either spring-loaded or free-floating. Both may move forward during the loading process when the face of the bolt hits the head of the chamber. Although the amount of forward movement is not intended to detonate the primer, slamfires occur when conditions do not match design assumptions. Cartridges which may be entirely satisfactory in manually loaded