A reusable "training" or "practice" round has a reusable hollow casing and a reusable hollow projectile that "snap together" and are releasably retained in assembled relationship by utilizing a resilient connecting member such as a groove-carried O-ring that is interposed between juxtaposed surfaces of concentrically interfitting portions of the casing and the projectile. The assembled practice round is inserted into the chamber end region of the barrel of a firearm and, when the round is fired, the casing is retained in the chamber as the projectile is caused to move along the barrel of the firearm and to discharge along a trajectory that closely simulates the path of flight of a "live" round. Propellant is provided by a reloadable or disposable blank-type cartridge. The projectile and the casing have hollow interiors that communicate and cooperate to define a closed chamber into which the blank round is fired to explosively generate the force needed to rapidly disconnect the projectile from the casing and to launch the projectile through the barrel of the firearm. A snap-together type of releasable connection is established between the casing and the projectile 1) by providing the casing and the projectile with coaxially extending surfaces that are brought into juxtaposed relationship during assembly of the casing and the projectile, and 2) by positioning a resilient connecting member to be tightly clamped between the juxtaposed surfaces just as assembly of the round is completed.