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Differences b/w .38-55 and .375 Winchester

2123 Views 9 Replies 5 Participants Last post by  Flash
I really want a Handi in .375 Winchester, but there is no chance of finding one. Can you safely fire .375 Winchester cartridges in the .38-55 BC barrel? Are the bore diameters the same? I know the .375 is slightly shorter, but how much?
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That's listed as an unsafe combo by SAAMI...


I wonder if that is based more on the fact that a lot of guns chambered in the .38-55 won't handle .375 chamber pressures. I know the Handi will handle even the hottest .375 Winchester loads, but I just don't know about shooting them in the .38-55 chamber.

I've been looking for a schematic on the .38-55 case, but haven't found one yet. If I can find one, it should be able to answer my question.
Here's a drawings page from Steve's pages...
The main concern about firing a 375 Winchester round in a 38-55 chambered firearm is the pressure. Chambering a 375 round in the 38-55 would be easy but unwise in an older firearm. I cannot advocate the practice of mixing the two rounds but I know what I'd do. :D
I interchange 38-55 and 375 Win brass regulary in my Win 94 375 BB. It was chambered for the 375 Win.

My 38-55 loads actually exceed the 375 loads in velocity. But I check my loads VERY carefully and SLOWLY work up to those levels. I get an avg. of 2130fps with 250gr bullets from a 20" barrel. Kicks like my 30-06 Savage.

The 375, pressure wise, is the same as a 308 Win, and 30-06. All go to 52K CUP, which according to SOME formulae is about 62,000 PSI.

If I had a 38-55, I'd just use 38-55 brass and load it to whatever levels I felt comfortable with. The Handi can easily handle the 375 pressures.

I'd think accuracy might be worse with the shorter 375 brass, unless you loaded long to compensate.
Well, the more I check in to it, its seems it would be a lot easier to simply stick with the .38-55 cartridge. It can be loaded just as hot as the .375, and brass seems to be a little easier to find.

Anyone know what bore diameter H&R is using in the Target?
Jason, if you do a search for 38-55 and select this forum from the list and choose all terms, you'll get 157's one of the good ones I got with 38-55 bore dimensions.....

Jason, the short answer is yes, the Handi will easily handle 375 pressures. The 375 Win operates at 52,000 psi with a case body diameter at the head that is smaller than the 30-06 which operates at the same practical pressures. I've fired quite a bit of 375 Win level loads in mine, no trouble. There is a slight mismatch of chamber dimensions to bore dimensions, and the bore is sized to the older 38-55 size of 379-380 on the groove diameter while the 375 Win is a true 375-376 on the groove diameter.

While a few are experiimenting with jacketed bullets in the Handi, I believe you can do as well with lead. The twist handles the Lyman 264 grainer (379449) quite well and pushes it at 1800 fps comfortably. I believe more is attainable, just don't have a chrono at present to be able to figure it out.

The main problem with the Handi and the 375 is not pressure but bore size. A couple of folks are making a 379 jacketed bullet, but makers like Speer, Hornady, Sierra are making a 375 bullet and it tends ot tumble in the .004" larger Handi barrel.

Do a search, cheatermk2 has done a bit of experimenting on this line with the Winchester bullet (no longer a component production item) there has been a good bit of disscussion on this subject over the last several months.

I don't think you can go wrong with even a 250-270 grain lead bullet at 1700-1800 fps. Such loads have worked for close range work on deer and black bear and hogs for longer than we've been walking around, at it's worst the 38-55 is the ballistic twin of a 44 Mag rifle, with a better bullet.
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OOOOOOOH, We must not type these words of damage, the Moderator police might get us. See Ruger firearms 30 Blackhawk!!!!!!
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