Pappy
As you know the 38-55 was first. They used the same case and made the 30-30.
I use 30-30 brass for my cast loads in my 375. The 38-55 and the 30-30 were not high pressure rounds. Unless the barrel is very thin I would have it re-bored with no concern.
I wouldn’t be concerned with 38-55 loads, personally. I would measure wall thickness at 375 pressure.

Last edited by Bugger; 09/02/22.
I prefer classic.
Semper Fi
I used to run with the hare. Now I'm envious of the tortoise and I do my own stunts but rarely intentionally