Can you??
 

I'm pretty sure the answer is yes but can you use 375 Winchester dies to reload .38-55 ammo?

I'm not a expert, but from what I read in my Lyman Manual, 49th edition, I would say no.

Let me quote the last three sentences which talks about ammo not reloading ...
"Never put a 375 Winchester round into a 38-55 Winchester. Nor should you
attempt to use 38-55 ammo in the 375 Winchester. Incompatible neck diameters
can cause serious hazard.
According to the diagrams in the manual there are some small differences in case diameters
and a somewhat bigger difference in the neck diameter. Since it's a rimmed case it going to
head space off the rim so the difference in case length may not matter.

I'll wait and see what others say

Gonna say yes, according to buffalo bore the cases are close enough to be interchangable.
https://www.buffalobore.com/index.ph...uct_list&c=175
try one and see if it chambers.
oonly problem I see is perhaps you may have to change the expander ball if the neck tension is to light.

I was only function testing, but I did some work on a Big Bore 94 last year and needed ammo - I used 38-55 brass I had on hand from my Cowboy Action side stage days with customer supplied 375 dies to make dummies. Neck tension and brass thickness, chamber support, should be a quick spec check.

I got a deal on 130 new .38-55 brass (4 boxes of 20 and a bag of 50) so I grabbed them. I do have a 375 Win and I can trim this brass down to 375 Win length and use them in my Big Bore. But what I'm really hoping is to find a nice old 1894 in .38-55 and use them in it. I just got to be very careful not to shoot any of the 375s out of it. I think all I would need to load the .38-55 is to adjust the 375 dies for bullet seating.
I was able to easily chamber one of these brass in my 375 but that was without a bullet. I may just try and seat a bullet and see if it chambers.

https://saami.org/wp-content/uploads...sting-Copy.pdf

why not look up the chamber and case differences and reload data

I did and the only major difference is the 38-55 case is slightly longer which is not a problem as I can trim them down. Also it looks as though the 375s brass is about .004" thicker based on the images I saw on line. Everything else is close enough. As for reloading data the .38-55 is loaded to milder pressures. From what I understand you can shoot 38-55s out of a 375 Win but not vice versa. The 375's pressures are too high for the 38-55.
I guess I should have rephrased the question. Can I load 38-55 brass up to 375 pressures without having any case ruptures?

the difference in increased velocity, if you reloaded 38-55 brass to drive bullets of identical weight, at 375 win pressure levels is not worth the increased risk , incurred with use of the thinner brass case in my opinion.

Well to answer the question yes you can use 375 Win dies for 38-55 Win even without trimming. I sized, flaired, and seated a bullet to the max 38-55 length of 2.550" and it dropped neatly into the chamber of my Big Bore 94.
Hardcast as far as pushing the 38-55 brass to 375 pressures rest assured that I see no reason to do that. I don't even load my 375s up hot. No deer is ever going to know the difference of a few fps at the ranges I will be using the rifle. And the 38-55 has been killing deer for decades.

yeah, most hard cast projectiles can be both very accurate and very lethal ,
without the need to have the handloads reach the max potential velocity.