38-55 VS 375Win..?????

[rbertalotto]

I recently bought a couple of rifles in 38-55. A Lyman Mini Sharps and a Winchester 94.
I also have in my collection a 14" Thompson Contender barrel in 375 Winchester

So I looked in a reloading book and I see that the two cases are nearly identical. And sure enough, in all three firearms, both cartridges fit with no issues.

Very strange that the 375 is a bit shorter than the 38-55. This allows a 375 case, at upwards of 52,000CUP to fit and fire in a 38-55 with a limit of 28,000CUP. I would have thought Winchester would have made the 375 longer so this couldn't accidentally happen. Especially in older, Black Powder, guns...........

I measured five cases of each:

The 375Win average 146.6g and the 38-55 cases average 136.0g in weight
The 375 length average 2.006" and the 38-55 average 2.075"
Just above the rim, both cartridges are .414 and at the mouth, both cartridges are.390 (new, unfired brass)

I would imagine it is totally safe to fire 38-55 cartridges in my TC 375Win barrel...........(but certainly not the other way around)






Anyone have any experience with this?

[damienph]

I fire 38-55s in my 375 XTR, never had a problem.

[elmo123]

I have a BB375 and 38-55's are too long. The bullet diameter of the 38-55 factory loads are .379 versus .375 for the big bore.

I loaded for a friend that had a Savage 99 in 38-55 and I loaded some cast loads, low velocity, in some 375 cases and they did not group worth a darn. The same charge in 38-55 cases worked very well. I guess it depends on the depth of your chamber on the 375 whether or not the 38-55's will fit. In the interest of safety I would not do it. I have used 30-30 cases with reduced cast loads in my 375 with good results. If you section a 30-30, 38-55 and a 375 you will see that the 375 is quite a bit thicker in the web.

Mike

[rbertalotto]

In the interest of safety I would not do it.

Would not do what?

38-55 in a 375 chamber?

[elmo123]

Fire a 38-55 in a 375.

[AJMD429]

It does seem like they could have made the more modern version not chamber in the older guns, but then again, it's kind of like the .45-70 hot/modern vs. the 'vintage' loads can all fit in the same guns.

[Blaine]

Buffalo Bore has a Heavy 38-55. A real stomper that they say will fire in any 38-55, or .375

https://www.buffalobore.com/index.php?l ... tail&p=159

[damienph]

Buffalo Bore has a Heavy 38-55. A real stomper that they say will fire in any 38-55, or .375

https://www.buffalobore.com/index.php?l ... tail&p=159

E-mail them and ask; they say that you can fire their 38-55 loads in a 375 chamber. I probably fire more 38-55 brass (winchester brand) through my 375 XTR than I do 375 brass. I have had no problems what so ever in my rifle, which is a top eject Big Bore XTR.

[Old Savage]

Keep in mind there are two lengths of 38-55 brass. The shorter and newer is 2.080", that fits in Marlins and modern Winchesters. I believe the longer measures 2.125". That may not fit.

Here is an article:

http://archives.gunsandammo.com/content ... 3855-brass

[damienph]

Keep in mind there are two lengths of 38-55 brass. The shorter and newer is 2.080", that fits in Marlins and modern Winchesters. I believe the longer measures 2.125". That may not fit.

Here is an article:

http://archives.gunsandammo.com/content ... 3855-brass

I just went and measured some of my new unfired brass; WW-Super 375 measures 2.013" and WW 38-55 measures 2.080". That is new brass right out of the bag. Measured several pieces, did not average, they were consistent length. All of my brass for this rifle was purchased new, I've never attempted to chamber any other brass in it.

[Blaine]

Buffalo Bore has a Heavy 38-55. A real stomper that they say will fire in any 38-55, or .375

https://www.buffalobore.com/index.php?l ... tail&p=159

E-mail them and ask; they say that you can fire their 38-55 loads in a 375 chamber. I probably fire more 38-55 brass (winchester brand) through my 375 XTR than I do 375 brass. I have had no problems what so ever in my rifle, which is a top eject Big Bore XTR.

I didn't intend to give the impression that I didn't trust that info....I have no reason to disbelieve Buff Bore claims....

[new pig hunter]

over the past few years I've chosen to shoot .38-55 through my Win BigBore94. No problems. "Accuracy" isn't the best since the load doesn't seem to be optimal for that particular rifle. But it makes for fun plinking with another caliber.

Oh, and I have the shorter .38-55 brass.

Cheers,

Carl

[damienph]

Buffalo Bore has a Heavy 38-55. A real stomper that they say will fire in any 38-55, or .375

https://www.buffalobore.com/index.php?l ... tail&p=159

E-mail them and ask; they say that you can fire their 38-55 loads in a 375 chamber. I probably fire more 38-55 brass (winchester brand) through my 375 XTR than I do 375 brass. I have had no problems what so ever in my rifle, which is a top eject Big Bore XTR.

I didn't intend to give the impression that I didn't trust that info....I have no reason to disbelieve Buff Bore claims....

Blaine, I didn't think that you meant that at all. I was agreeing with you, in a round about way. For years, I only fired 375 Win ammo in my rifle because of all of the stuff I read about 375 and 38-55 not being interchangeable, either way, in either rifle. I saw the Buffalo Bore ad for their "hot" 38-55 being suitable for firing in the Winchester XTR rifle. I e-mailed them and asked and was told, in writing, that they guaranteed no problems shooting their ammo in my rifle. I've been doing it with no problems ever since.

[gundownunder]

I was recently reading an article on just this subject and an interesting theory was proposed. Sorry, I can't remember where I read it.
Normally they make a magnum longer than the original so that it won't chamber in the lesser gun. In the case of the 38-55 / 375 the original chamber was already as long as the action could handle so lengthening was not an option. Apparently the thinking behind the shorter case was that if it was put into the longer chamber there would be a little pressure expansion space before the bullet hit the rifling, couple this with the fact that the 375 is a .375 and the 35-55 is more like 378 - 380 an incorrectly chambered round would fire without reaching maximum pressure, and hopefully without catastrophic failure of the rifle.
Does this mean it is safe, hell no, but "hopefully" the gun won't blow up in your face.

[handirifle]

I would never recommend shooting a 375 in a 38-55 gun, ever, but, I would also guess, that if someone did it by accident, the fact that the 38-55 bore is .379 and the 375's bullets are .375, there's a real good chance the gun wouldn't blow up. i think the larger bore would prevent pressures from reaching anywhere near peak like they would in a true 375 rifle.

But as I said earlier, I would never try it or recommend it.

as to why Winchester did what they did, I have no idea.

[Old Savage]

I personally don't see that there would be a problem shooting 375 Win ammo in any modern 38-55 rifle that is also chambered for the 375 Win such as the Win BB or the Marlins.