The 38-55 is a lo pressure caliber, and as such should be even quieter than a handgun cambering when made into a shorty. (255gr at 12-1300fps)
BUT the way Tim loads his,

its going to be as loud if not louder than any short 30-30, as he just confirmed.

A good example is the 30 Carbine. many of us have fired one from a carbine, its nothing special or extraordinary. Now load that puppy into a short hand gun barrel like my Blackhawk and WHOA!! This baby BARKS with authority!!!
CW