12 which includes a front adapter assembly 15 and a rear adapter assembly 17 coupled together by spaced apart upper and lower adapter rods 19u and 19l which extend between the front and rear adapter assemblies the frame 12 also includes a breach block stop 21 that is coupled to the rear adapter assembly 17 and extends rearward from the rear adapter assembly referring to fig1 and 2 the frame 12 supports a barrel 23 that is mounted to the breach block stop 21 so that the barrel extends from the breach block stop through the rear adapter assembly 17 and through the front adapter assembly 15 to a location forward of the front adapter assembly a telescopic sight 25 is mounted along the length of the barrel 23 the barrel 23 and the telescopic sight 25 are located extending between the adapter support rods 19u 19l referring to fig8 a tank cannon 13 with which the device 11 may be used is shown the cannon 13 has a breach ring opening 27 through which cannon ammunition or the device 11 may be loaded into the cannon 13 the breach ring opening 27 extends through breach ring 29 the cannon ammunition or the device 11 is loaded into the cannon chamber 31 a breach block 33 is located rearward of the chamber 31 the breach block.