Late 1970s brass-framed 1860 Colt in .44 caliber. Made in Spain, as I recall.
Full loads of DuPont FFFG black powder, with .451 ball and Crisco. After a few hundred rounds, a negative imprint of the cylinder rear was impressed into the brass frame below the hammer channel. Wedge had to be driven in nearly flush to keep barrel assembly tight to frame. I don't recall checking the tightness of the cylinder pin, but it was probably loose in the frame too as this is a common ailment of brass-framed revolvers.
Gave up on brass-framed revolvers after that. I also realized, and still believe, that brass-framed revolvers are not as well made as their steel-framed counterparts. It's as though the factories slap them together, not investing as much effort in fit, finish, materials and the hardening of small but critical parts. There's a reason they're cheaper: they're not as well made. At least, that's my observation over 40-plus years of shooting cap and ball revolvers. Yes, there are some well-made brass-framed revolvers out there, and I've seen them, but they're not as well made as those made of steel.
My 2 cents worth.