Some time back, I saw on a gun forum where a gunsmith can rig a blast shield to deflect the burning gasses on a revolver rifle. On an original Colt rifle, something like that would certainly influence the value.
In the John Wayne classic film "El Dorado," Arthur Hunnicutt played the role of "Bull" an old Indian Fighter, who used a Colt Model 1855 Carbine (revolver). It didn't appear to be altered, but they did use blanks in the movie, and it looks like "Bull" was holding his support arm at an odd angle which may have been to avoid the escaping gasses.
For a really good time, check out the Internet Movie Firearm Data Base, http://www.imfdb.org/wiki/Main_Page
Warning, this site can become habit forming.
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