The 38-55 thru the years has used many bullet diameters. Factory loads use .376 diameter jacketed bullets if I remember correctly. My last Winchester Hiwall used .379 diameter. You can slug your bore or try a couple of bullets sizes to see what works best in your gun. I've used up to .381 in some 38-55's.
Times are tough - Keep your powder dry
"These are the times that try men's souls." - Thomas Paine