A safety device for preventing unauthorized or accidental use of a gun. The
safety device includes a solid body of material, a muzzle end plug and an
elongate threaded rod inter-connecting the same. The solid body is sized
and shaped to simulate a live cartridge. It has an outwardly directed
flange at one end for engaging an end wall surrounding entry into the
cartridge chamber of the gun and a threaded bore extending inwardly a
selected distance from the opposite end. An O-ring fits into a groove it
the solid body and projects outwardly frictionally to engage the inner
wall surface-of the gun barrel in the cartridge chamber. The muzzle plug
has an outwardly directed flange at one end thereof that engages an outer
end of the gun barrel. The muzzle plug has a recess in the outer end face
remote from the elongate rod and in a preferred embodiment beyond the
recess there is chamfered surface tapering to the extent that the
outwardly directed flange has a thin narrow edge that cannot be gripped by
pliers or the like. A key has a projection that mates with the recess in
the muzzle plug. A pin projects from the key projection and fits into a
small recess in the base of the first mentioned plug recess.
