flipping through a couple of reference books, I found a prototype Paterson in .53 caliber- circa 1833. It never went into production. Also found a Wesley-Richards .49 caliber.
I thought i would run across a .577 or two but don't remember if these were percussion or cartridge.
thanks for your answers, and yes there were two british 577 cal revolvers, the webley No1,and the revolver pryse, but they were alreadyy catridge firearms.
