When a shooting friend passed away, I inherited all is single shot and lever gun ammo. I have 2 boxes of his 38-55 black powder loads. They won't chamber in a modern rifle with a .375-.377 bore, these have bullets that are .386! 38-55 was a Ballard round that Marlin used after they bought Ballard. Winchester picked it up and put their name on it (but I find no differences!) The bore from rifle to rifle are very wild in their diameters! In my modern rifles I use .377 sized bullets with fantastic results.

All the factory ammo is safe to shoot in any age Winchester 94 or Marlin 1893 or 336, but accuracy may suffer. To load for the old guns you'll not only need a three die set, you will need an "M" die the correct size. While I have 2 bullet molds for 38-55 (255gr RNFP & a Pope design 330 gr RN), I've been shooting Bear Creak's moly coated lead 265 RNFP sized to .377. They sell sizes way up into the .380's! When I cast bullets for 38-55, and size them, lube them with SPG lube, it was invented for black powder, but is great with smokeless loads using large soft lead bullets. I use it exclusively with 45-70 and 45-90 cast bullets also. Good lube on proper diameter bullets have very consistent shot strings, and that's good for targets and good for varmints! (In some places White Tail deer are thick as varmints, that good enough for me!)

Ivan