Abstract: The barrel comprises a unit (1) for initiating detonation connected to a detonation chamber (2) accommodating a combustion-to-detonation transformation accelerator (3) in the form of a space lattice arranged coaxially inside the chamber (2). The size of each cell (4) of the lattice substantially equals the size of cell of a stationary detonation wave in an explosive mixture of preferred composition. The number of cells (4) of the lattice in cross section of the detonation chamber (2) grows toward an open end of the barrel defining through passages (5) for conveying gas from the unit (1) or initiating detonation to the detonation chamber (2). The peripheral passages (5) of the lattice are arranged at an acute angle (.alpha.) to the axis of the barrel.

Abstract: The arrangement comprises a housing (1), a hopper (2) containing a powder and communicating with the interior of the housing (1), and a slide valve (11) having a drive (9) mounted inside the housing (1) and provided with a powder-metering cavity in the form of a recess (12).The housing has through passages for feeding compressed gas, and conveying the powder from the hopper (2) to the recess (12) and from the recess to the barrel. The slide valve (11) is arranged at the top part of the housing (1) and resiliently urged thereto in the zone of outlet holes of the passages. The arrangement also has a shut-off unit (18) connected to the slide valve (11) to block the outlet hole (8) of the passage for feeding the powder from the recess (12) to the barrel in one of extreme positions of the slide valve (11), in the other extreme position thereof the powder-metering cavity (12) communicates with the outlet hole (8) of the passage conveying the powder to the barrel.