Hi Kevin It looks like a Beaumont Adams, model 1855, 1856 or 1860, five shot calibre .44. They were made by London Armoury and Robert Adams Company in England. There are differences between the models, barrel length and minor details but I could only find one good picture of one of the models. I could also be a revolver by William Tranter, which is an improved Adams. They came in at least 6 different calibers from .36 and up. The earliest were percussion and the latest ones took centre fired cartridges. I got one cartridge in .50. This model got a lot of variations on barrel length, hammer types and other details details. Kjell