Abstract: A plug is inserted into and withdrawn from the muzzle end of a gun barrel by means of an external grip to store the gun in a safe condition with a dummy cartridge in its firing chamber. A retainer formation within the dummy cartridge is engageable by an elastically deformable lock device fixed to the inner end of the plug so that the plug may be respectively locked to and released from the dummy cartridge by opposite insertion and extraction forces of different lock engaging and lock releasing magnitudes to prevent loading and unintended firing of the firearm.

Abstract: Bench tool mounting apparatus has a single rectangular outer part for fixing to a work bench work station and that defines three interior three-dimensional orthogonally contiguous marginal areas adjacent three outer part sides and center openings on a fourth side. There are also a plurality of inner identical parts, each for having a bench tool fixed thereon and each defining three three-dimensional marginal projections adapted for each to slidably engage in the marginal areas of the single outer part through the center openings thereof and thereby securely mount a bench tool on the work bench. A pair of bolts engage respectively in vertically aligned and spaced-apart bolt holes defined through an inner part marginal projection and an outer part defining an adjacent marginal area to lock the inner and outer parts together.