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

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). L'invention concerne une cartouche inerte. Cette cartouche comporte une douille 1 sertie en 5 sur un projectile 2, et est originale en ce que le projectile 2 comporte un prolongement longitudinal 2a engagé dans la douille 1 déterminant ainsi un espace annulaire avec la paroi interne de la douille; le projectile muni de son prolongement comporte un trou borgne 9 pratiqué longitudinalement; l'espace annulaire est rempli d'un liant 3 à retrait négatif. Cette cartouche inerte est utilisable notamment lors d'exercices de manipulation d'armes.