You do realize of course, or maybe you don't, that when you cock one of the open tops there is no B/C gap because the hand pushes the cylinder forward against the rear of the barrel. Having a large B/C gap does several things none of them good. First it puts the cap further from the hammer when it falls lessening the impact and in extreme cases causing misfires. Then as the gun fires it allows considerable fouling to be deposited on the arbor which gets directed into the space between the arbor and cylinder causing binding after only a few shots. It also allows the cylinder to pick up speed as a projectile in recoil causing additional wear.M.D. said:I don't even re-barrel my smokeless revolvers that close.
Dan Wesson revolvers are the only wheel guns I have ever seen set at .002 and they usually are set up for high velocity smokeless loads for silhouette use.
Smith and Wesson and Colt D/A revolvers are recommended set at .004-.006 with a minimum of .003 and max of .008. The Same standards apply to Ruger Single actions.
With a .002 cylinder gap many of the reproduction guns would rub on the six or twelve o'clock chamber as most arbors and base pins do not keep the cylinder in perfect square or coaxial alignment with the bore and breech face. Actually, modern revolvers seldom have perfect square with cylinder faces either.
The fault here is the threaded barrel hole and square barrel seat through the frame on solid frame guns and the arbor alignment or wedge fit on open frame guns.
From the factory no it would be an added expense and Uberti can't even be persuaded to get the arbor length correct which is majorly why things can appear out of square. Pietta in the last few years has it pretty much down pat with the arbor and B/C gaps around .004 generally.M.D. said:I respectfully disagree! I have never seen any black powder revolver original or reproduction purposely set up with a .002 cylinder gap from the factory or any where else.
Most all of them are on the generous side of .006 and virtually none of them are square with the breech face.
I do however believe that any thing over .008 is two much for any revolver percussion or otherwise.