If you are loading cast for a 38-55, better slug the barrel and find out what the groove diameter is. [Very high chance it is NOT .375"]
They usually run from .377 to .380" somewhere.
Cast shoot best .001 - .002" over groove diameter.
My 38-55's groove diameter is .3775" and shoots a .379-.380 cast bullet very well.
The 220 grain, 375 Winchester bullet from Hornady is a true .375", and will not shoot well in all 38-55 rifles.
My 1980's vintage 38-55 keyholes this bullet
Barnes makes a beautiful 255 grain original expressly for the 38-55. [P/N 38/5520]
It is .377" diameter.
Be careful!! They also make a similar, 255 grain, .375" bullet for the 375 winchester.
[P/N 375W20] The crimping groove is located differently.
If you load the 375W bullet in a 38-55 case and crimp in the groove, the loaded round will be too long to cycle through a Winchester M94 Action.
I am very pleased with my 38-55, and have some very accurate cast & Jacketed loads for it.
Also shot my second largest Whitetail deer with it.
What is not to like!!
Regards, Eagleye.