Six-round conversion cylinder converts steel frame, cap and ball revolvers to modern centerfire. Patterned after an original Remington design for a drop-in fit. Cylinder and back plate fit together without screws. To reload, just drop the cylinder, pull the plate off and dump the fired cases. Use in steel frame guns only, with black powder equivalent loads. No FFL required to purchase. Models for .44 caliber, 1858 Remington Italian replicas, Uberti and Ruger® Old Army™ are chambered for the .45 Colt cartridge. Mfg: Taylors And Co. SPECS: Steel, blue, polished finish. Old Army™ - Blue, polished or stainless steel finish. Chamber length - 1.625" (4.1cm). May require fitting to base pin.?