Chambered for British .455 cartridge. Marked on right side of slide British Broad Arrow" proofmark will often be found. Pistols were made in 1915-1919 and follow same numeric serial number sequence as normal Government models, except "C" prefix was replaced with a "W". They are commercial series pistols. Magazine well of these .455 pistols is slightly larger than a standard Cal. .45 Auto pistol and will accept a Cal. .45 magazine, but a standard Cal. .45 will not accept a Cal. .455 magazine. All pistols in W19001 to W19200 range, as well as some in W29000 range, are believed to be JJ marked above left trigger guard bow. Add 25 percent for JJ marked. Some pistols in C101000 to about C109000 range have RAF marks as well as a welded ring in the lanyard loop. Most RAF pistols have been re-finished and many have been converted to .45-cal. by changing barrels. Re-finish=Fair/Poor. NOTE: Add 20- to 50 percent for finish 99-100 percent; 25 percent for RAF. Deduct 35 percent for wrong barrel.