Abstract: An improvised projectile checking housing assembly having latch button and first and second sidewalls with first and second catch apertures opening as a catch latch recess of elongated structure using an improvised projectile checking spring opening to receive a locking key structure based upon the projectile receiving opening to the improvised projectile checking housing assembly. Alternate rearward translating lock gauge at the backside of a dart drum uses a follower and engaging cam surfaces locking and unlocking a pathway for correct dart alignment. Alternate motorized, non-motorized and pneumatic structures are disclosed with apparatus launch operations moving between checking and non-checking positions.