U.S. Patents # 6,634,128 and 7,562,478

This is a cartridge converter unit kit used to convert Civil War Era black powder  cap and ball revolvers to metallic rim or center file cartridge revolvers and reduces the revolver's caliber to .22 caliber rim fire or .32 caliber center fire.  If so desired, the gun can fire balls again by removing the conversion kit from the gun.  No restrictions.  It can be used safely without restriction in brass frame or steel frame, open top or solid frame revolvers.  It is not restricted to fire low pressure cowboy ammunition.  Can be used any economy .22 caliber rim fire or .32 caliber center fire ammo.  It is a drop-in system meaning that the gun to be converted needs no alternations in order to install the conversion unit.  No tools required to install the kit except for open-top revolver which needs a screwdriver to loosen the barrel wedge screw.

Patents available for license.

The Original Caliber Reducers & Converters by Vastag

gun converters by Vastag