VOREStation/code/__defines/projectile.dm

#define HOLD_CASINGS	0 //do not do anything after firing. Manual action, like pump shotguns, or guns that want to define custom behaviour
#define EJECT_CASINGS	1 //drop spent casings on the ground after firing
#define CYCLE_CASINGS 	2 //experimental: cycle casings, like a revolver. Also works for multibarrelled guns
	`#define HOLD_CASINGS 0 //do not do anything after firing. Manual action, like pump shotguns, or guns that want to define custom behaviour`
	`#define EJECT_CASINGS 1 //drop spent casings on the ground after firing`
	`#define CYCLE_CASINGS 2 //experimental: cycle casings, like a revolver. Also works for multibarrelled guns`