I am sure this has been discussed here

[S.S.]

But what is the proper way to adjust the cylinder gap on
an open top BP revolver. It appears that you just would drive the
wedge in deeper to close it up but that does not seem to be the case.
Maybe take a few thousandths off the bottom of the arbor? but then you would have to pull the two pins that hold the barrel and take a bit off there too?
Any opinions on the best way?

[halfslow]

I have removed a few thous from the front of the frame (after pulling the pins) on an 1860 when the gap was excessive (like .030).
Remember that the arbor is supposed to bottom in the hole in the barrel when fitted correctly.

I have sent you a PM

[Pat/Rick]

If it is a well used revolver and the gap is exessive, I would try a new wedge first, and limit any fitting file work to the wedge first. If that didn't help I would then take a small file to the cylinder pin wedge slot, but only file on the slots front edge. I would scrutinize and think through Every aspect before filing on/in the cylinder pin. Wedges are the cheapest starting point, start there and go carefull. All adjustment is meant to be wedge pressure. Good luck.
 
 
Is it a brass frame??  If so, is it worn with cylinder indentation/imprinting marks on the recoil shield? If so, it's probably shot out. (Wallhanger or parts)...........