Abstract: A round of ammunition for use in training comprises a standard brass cartridge case (1) containing a reduced propellant charge (14) and a bullet (2) of standard shape comprising a core (3) of rigid polyurethane foam and an external skin (14) of unfoamed polyurethane. The core and skin can be moulded integrally. The round is designed for firing in an automatic weapon and actuating its automatic mechanism. The skin of the bullet should be not less than 0.02 mm thick to withstand handling, and not more than 0.10 mm thick to avoid production of large fragments thereof on firing. The bullet can have opposite ends both of ogival form to facilitate manufacture and operation. The round is mainly for small arms up to 10 mm caliber.