Yes you can shoot 38-55s out of your 375 Big Bore. The 38-55 have way less pressure than the 375s to be safe in the older rifles chambered for it. As for getting bullets for either in.377" good luck! I bought a mold and cast my own at .379" and they shoot moderately well out of my Big Bore 94. I'm still in the process of testing them. Powder coated or pan lubed to see which shoot better.
What I find interesting is that the 38-55 cases are slightly longer than the 375s. One would think it should be the other way around. But because both are rimmed cartridges it is a moot point anyway.
Last edited by ClemB; 08/24/22.
