I recently inherited a military revolver that was regrettably converted from .455 to .45 LC and I was wondering if it would still be able to fire .455 safely / reliably.
I'm pretty sure the conversion was done by boring the charge holes and shaving off the back of the cylinder since there isn't a serial number back there.
Probably. The headspace is a mite excessive, but as long as the hammer hits the primer hard enough, it will fire. .455 is a low pressures round so there shouldn't be a problem.
I had one years ago. I used the Keith bullet and had to deep seat it because of the length of the cylinder. It still shot fine.