Walker subsequently emigrated to South Africa, bringing with him the design for the Striker shotgun.

The rotary cylinder was bulky, had a long reload time, and the basic action was not without certain flaws.

[2] Walker redesigned his weapon in 1989, removing the cylinder rotation mechanism, and adding an auto cartridge ejection system.

[3][4] A copy of the Striker was made by the US gunmaker Cobray and marketed as the SWD Street Sweeper from 1989 to 1993.

[2][6][7] After a proposal by the Brady Campaign in 1993, Treasury Secretary Lloyd Bentsen declared the Striker and Street Sweeper destructive devices under the National Firearms Act the following year, their transfer and ownership becoming regulated by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).