Hey E,

The .375 has a bore of .377". The 38-55 is .380".

Would not recommend it.

Later, Mark

 

Ditto that, not recommended.

 

If you're talking 38-55 ammo, it isn't recommended, as msharley and Coyote Hunter have stated above. However, if you're reloading 38-55 Win brass to shoot out of a 375 win rifle, you can trim the brass to 375 Win specs and using light to moderate loads you'll be okay. I use 38-55 brass all the time for shooting and plinking and use the 375 brass for sighting in the scope and for hunting.

 

Thanks for your input !!

 

When I bought my Marlin .375 new I bought some .375 brass and some 38-55 brass. I trimmed the 38-55's down to .375 length and use them for cast bullet loads. The .375 brass gets loaded to full power with jacketed slugs.

 

the buffulo bore heavy 38-55 ammo on there website states suitable to use in 38-55 and 375 winchester rifles suited for smokeless powder has anyone have any knowledge of this ?????

 

On the upper end loads the .375 brass is stronger.

 

Just as an addition to Swany's pictures I weighed some empty cartridges on my RCBS digital scale. Results= 30-30 RP cases average 130.2 grains, 38-55 W.W. cases shortened to .375 Win. length ,135.7 grains, 375 Win cases 146.8 grains . Just for a reference .358 W.W. cases 176 grains. So as
Swany's cut-aways show the .375 cases are a lot stronger for the increased pressure of the .375 Win round.

 

are the heavy 38-55 buffulo bore ammo designed or trimmed to shoot in a 375 winchester ?? i did not know if anyone knew of this ammo they offer??

 

I think your OK as long as you don't use the 375 Winchester ammo in the 38-55.

 

Bear in mind the .38-55 has a larger bore size (up to .382") and bullets for it are typically .379" or larger. Shooting .38-55 ammo in the .375" bore of the .375 Win could easily result in unsafe pressures and nasty surprises.

Your gun might survive, as might you. But why risk it?

 

I use starline 38-55 short brass, trim to size, load it to 1800 fps 200gr bullet and go hunting, welcome 1006 !!!

 

Also, note that the 375 Win has a 2.020" long case; 38-55 case is longer. Starline produces two lengths of 38-55 - 2.080" and 2.125".

 

Perhaps someone can explain to me why there always seems to be someone who wants to use ammo in a firearm for which it wasn't designed. Either 38-55 or 375 are still available with a little looking and either can of course be reloaded. I guess it's human nature to try something "different".
Jim

 

I'm with you italiansport.... I do not see a reason to do this. Both are available so use what the rifle is intended to use.

 

Buffalo Bore Heavy .38-55 is recommended, right on the box, For use in rifles chambered for the .375 WCF. Works perfectly in my BigBore 94. Doubt if it was unsafe, they would be so stupid to open up themselves up to this type of liability. Anyway, theirs shoot fine in mine.

 

Years ago I decided to use only brass intended for the gun, if it is available. A few months ago when I got back into fooling with 375
I did blow out 30/30s to make a few boxes, but was not stupid enough to put 375/ jacketed loads in these cases. If you feel the need
to do this, I would suggest using loads for 38/55 cast. I'm not into target shooting with 375, so 100 cases is enough for me, even at
$1@. I have read various articles where a "expert" is telling people you can substitute x for Y. Yes you can detonate several different
cartridges in guns with the same head, and same parent case. That doesn't mean it's safe or accurate.

 

This question comes up regularly. 38-55 and 375 Win or two distinct cartridges and their respective rifles have distinct chambers and bores. That being said, they are similar enough that one cartridge PROPERLY PREPARED AND LOADED can be shot in the other rifle. I do it and others on here have posted that they do it to no ill effect. I am talking about reloading 38-55 brass with the proper sized bullet to fire in the 375 Win chamber. What is the proper size bullet? You have to slug your bore to find that answer. You should not rely on hearsay from anyone or even on published specs, they may be off by several thous of an inch. As others have stated before, you do not want to try to PUSH A GOLF BALL DOWN A GARDEN HOSE ! But you CAN push a .379 cast lead bullet through a .377 Marlin bore. In fact it is recommended to run a cast bullet one to two thous larger than the bore. When I shoot jacketed bullets, I run Hawk .377 soft copper jackets. I have never had a problem with the 38-55 brass length. The throat of the Marlin chamber is long enough to handle 38-55, but I choose Starline 38-55 1.08" (short) brass. The other question was, "Why would anyone want to shoot a cartridge in a firearm for which it was not designed?" I'll tell you, the same reason so many shoot 223 in 5.56 chamber. The same reason we shoot 38 Spl in 357 mag. The same reason we shoot 22 short, long and LR in the same chamber. BECAUSE OF INTERCHANGEABILITY and BECAUSE WE MAY HAVE TO OUT OF NECESSITY and BECAUSE (if we pay attention to detail) WE CAN. I do not advocate shooting factory or full-house 375 in a 38-55 rifle, either new or vintage. If you are not comfortable or don't have the knowledge to reload, I don't advocate you doing what I do either.

 

Ok, help me put a giggle check on 375 Win loads for a 375 Win using 38-55. As has been pointed out many times, the 38-55 brass is thinner and therefore, conventional wisdom says that you should not use max loads. If I am not mistaken, the 38-55 brass is just as thick as 30-30 or 32 spl brass. Here is the giggle check. Max psi for the 375 Win is 42k psi. Max psi for the 30-30 and the 32 spl is also 42k psi. If that is the case (pardon the expression) why should I worry about 42k psi in 38-55 brass when used in a gun that is designed to handle 42k psi?

 

30cal doesn't worry about it, hence post #21. The problem arises where you might have a chamber that has been altered or is overly generous. This is when you get a lot of case stretch during firing. 38-55 brass in a close fitting chamber with reasonable powder charges can and is often used safely. Knowledge, experience and common sense dictates. Shoot safe.

 

where you may get in trouble is when you have a short chamber and with the longer brass you don't have bullet release, thereby spiking pressures. i have a short chambered AR that i have to trim brass so short for i can't use a lee factory crimp die . have a finish 5.56 reamer on order.
with the way stuff is coming from remlin, i would not be surprised to see short/tight chambers and other weirdness.