Although quite simplistic and not commercially successful, Thuer Conversion was the first attempt by Colt to convert percussion revolvers to the new metallic cartridge system. This conversion was designed around the tapered Thuer cartridge. Consists of a ring that replaced the back part of cylinder, which had been milled off. This ring stamped "Pat. Sep./15, 1868". Ejection position is marked with letter "E". These conversions have rebounding firing pins and are milled to allow loading from the front of revolver. This conversion was undertaken on six different models listed; all other specifications, finishes, markings, etc., not directly affected by the conversion would be the same as previously described. From a collectible and investment standpoint, Thuer Conversion is very desirable. Competent appraisal should be secured if acquisition is contemplated. NOTE: Blued models will bring higher prices than nickel models in the same condition.