Hey Sundance,
I don't know about a Pietta, but I traded a pocket knife for a never fired Armi San Marco brass frame 1851 Navy in .44 caliber for my son. If the Peitta is anything like the ASM, save up and buy a Uberti. As stated prior, there were no .44cal Navys.
We were shooing 15 and 20grs of FFF and sometimes the action would lock up. There was something in the action that if you just let the hammer down on a nipple (uncapped), it would lock up. You had to fire it to have the cylinder rotate. Just letting the hammer down very easily wouldn't do it. There was a tiny bit of play in the action. I have a Uberti 51 Navy, never had any problems with it at all. Like I said, if the Pietta is anything like an ASM, pass. IMHO, Uberti is the top quality Italian repro.