Marlin 375 Winchester

[Fastleo]

Snagged a new to me marlin 375 Winchester, looking for load advice. Thanks

It’s the bottom rifle, above gun is my 444.

[Der Gebirgsjager]

Nice catch! I always wanted both a Marlin .375 and .356 to complement my Winchester Big Bore '94s in those calibers. Hard to find now days.

DG

[jreidthompson1]

From 2002 Hodgdon manual found online

[jreidthompson1]

From 2000 accurate guide found online

[nhithaca]

I also have one of these and mostly use the Accurate load data w/ AA1680. Pretty much all of the top loads will be compressed to some extent. Be aware that the test guns all or mostly all had 24" barrels and you will not get the speeds quoted (Marlin 375s are all 20"). If using cast, make sure that you are not using undersized bullets. Mine likes 0.377". May or may not fit your chamber. Barrels on the Marlins are Micro-grooved, have a twist rate of 1:12 and tend to be larger than 0.375". On the positive side gun is mostly accurate will all loads I have tried. And you can generally use the newer shorter 38-55 brass with no issues (please check however).

[ohiochuck]

Loading Data for 375 Winchester
from Pet Loads by Ken Waters and
Accurate Smokeless loads # 1

[Fastleo]

Thanks for the responses, I’m so far interested in the Sierra 200gr and the speer 235 speer. I know shooting cast in a micro groove has been done but I’m not sure I want to start with it. I’m going to at least try to find those bullets to start. So far nobody has them in stock, so I get to play the waiting game with another dead caliber.

[nhithaca]

Speer used to show data for their 235 but with a warning about the pointed bullet in a tube mag issue. Also, the 235 does not have a crimp groove so either you cut one (there are tools available) or you get a Lee Factory Crimp die and firmly crimp the bullet. I also contemplated filing the lead tip down so the bullet would not impact on the primer of the case in front while in the tube mag but you would have to come up with someway to make all the bullets the same weight. Lastly be aware that the OAL of the round with the 235 bullet may be close to the max for the 336 action. Mine wants the OAL to be 2.6" or less.

[ohiochuck]

as ntithaca mentioned watch the Speer in the tubular magazine

[Jeff Michel]

200 grain Sierra and the max load of RL7 (Lyman 50th)

[Fastleo]

200 grain Sierra and the max load of RL7 (Lyman 50th)

I think that’s going to be the bullet by the looks of it, now to find them in stock…

[TomAM]

The Marlin 375 is really just a 38-55 with a different stamp on the barrel.
Producing good loads is much easier once you realize what size of brass and bullets really fit.

[Dan Cash]

I have some 250 grain bullets that I think are .278 or .280 that work well as cast in my 1893 Marlin .38-55. If you would like to try some, PM me. If interested I will put a mic on them in the AM and provide details.

[Fastleo]

I have some 250 grain bullets that I think are .278 or .280 that work well as cast in my 1893 Marlin .38-55. If you would like to try some, PM me. If interested I will put a mic on them in the AM and provide details.

Mighty fine offer sir, I’m going to try to avoid cast with this one.

[farmbif]

all this great load y'all are finding,
I only have 3 molds for the 375 win all all of them seat so deep that its basically fill the case with 4198 or 1680 to where the base of the bullet is and I'm good
1680 does not compress. I for one sure do enjoy the 375 win. there was a guy out in California making a duplicate of the Hornady 220 grain, I still have some of those but not really a need to use them as long as I have a bucket of wheel weights.

[FergusonTO35]

Good score! Still kicking myself for passing up a nice one for $400.00 a few years ago when nobody wanted the .375 chambering.

[Fastleo]

Good score! Still kicking myself for passing up a nice one for $400.00 a few years ago when nobody wanted the .375 chambering.

Ooof, I really wasn’t looking for one to be honest, I was just browsing arms list and I came across it. It just wanted to come home with me.

[FergusonTO35]

Ooof, I really wasn’t looking for one to be honest, I was just browsing arms list and I came across it. It just wanted to come home with me.

I think this was before it became common knowledge that most .375's will take .38-55 brass no problem, and people saw it as just a 336 which required expensive unicorn dust ammo.

[yeahbub]

FergusonTO35 is correct on most .375 Win chambers being cut long. Back in the day, I used the 2.080" .38-55 cases in a Marlin with full throttle loads with no problems. A note of caution, though, there are two lengths of .38-55 brass, 2.080" and 2.125". Measure the chamber in your rifle to see whether the 2.125" brass is too long.

That 375 Marlin had a barrel constriction at the rear sight dovetail, but once it was pressure-lapped out, it shot paper patched excellently. The load that was safe in mine was the Lyman 375248 (250gr of WW) paper patched and sized .378, over 28gr of AA1680, Win LRP which shot into 2 - 2.5" at 100 yards. IIRC, that was as far as I wanted to take it - twenty of those and it got to be more like work than fun. Being paper patched, it could have been cast softer for hunting but deer around here probably wouldn't have shown any expansion.

Good luck with yours.

[quilbilly]

Don't give up on cast for it yet. If it shoots plain base cast as well as my Marlin 444 micro groove barrel, You will definitely have fun with it.