Practice-type 20mm cartridge - is empty of propellant with projectile lengthened and hollow to maintain weight and balance

摘要

The dummy 20 mm bullet has a case (1) which is emptied of propellant. A stopper is used to replace the primer in the base (8). The case is crimped to the projectile (2) in the usual way (5), and can be steel or brass. The base is lengthened by 44 mm and is made of steel. To counteract the extra weight of this lengthening, the projectile is hollowed out for most of its length by a hole (9) of about 13.5 mm dia. On the lengthening (6) is machined a recess. A joint (3) is placed in the space between the case and the recess and held by a stopper (7).