.375 Winchester

[softpoint]

Today, I aquired a rifle in a caliber Ihave never before played with. I came across a Marlin in .375 Winchester. Rifle is clean ,I'd say the metal is near 99%, wood has a few handling (or storage) marks. $300 even, with a cheap Tasco scope, 1 box of factory ammo. I fired 3 rounds , all touched at 50 yards, rifle is sighted in.
I'll probably put on a reciever sight once load development is done.
Idid have a contender barrel once years ago in this cal. but never did any load development for it.
So, the question is ,who makes a suitable mold for this rifle?, I see that both Lyman and Rcbs make a gascheck version and Lee makes a plain base. I will probably get the Lee for a light load mold, and one of the others for a hunting load. It has Microgroove rifling, so I'm guessing a mold that throws a large boolit?
I have a .377 sizer here, will that be large enough. (I haven't slugged the barrel yet) Some molds are slightly larger, I'm assuming for the 38/55? but I don't see one of those listed with a gascheck base. Who has worked with a rifle in this caliber, and what were your results?

[fredj338]

Nice find. I would have paid that in a heart beat.

[runfiverun]

so far i haven't used a g/c mold just the magme 260 rnp but i'd get the flat base next time.
with h-322 and a filler i got just at 1400 fps but it shoots too low at 50 yds for the factory sights,nice groups though my win will shoot this load o pai at 100 yds.
oh yeah i use win 38-55 brass as it is longer than 375 brass.
i haven't tried the saeco 571-572 mold through mine yet but they are closer to 300 grs.
for the higher end you will want the lyman gas chech 375 mold and 379 is just fine for a size,in both the win and marlin it will even workin my 375 super mag reolver.
maybe nolan has some more experience with other molds.

[softpoint]

Wonder if the Lyman or the RCBS casts the larger diameter boolit?:coffee:

[garandsrus]

Hi,

I really like 375449 which is a gas check mold. I size them to .379. If you want to try some, I probably have them already cast/sized/lubed.

John

[onceabull]

Softpoint: although there is not a thing wrong with either the Rcbs 37-250,or the lyman 375449 design,either make may turn out to cast a tad small for your rifle..Lyman's work fine in my 375 BB,or the Sav 99,but mine doesn't drop large enough for my Marlin 375. Without a chance to try before paying,you may be disappointed.. If you can be happy with something lighter,I'd recommend NEI's 377-210, and tell them to make it to whatever you need diameter wise(It will probably be fine ,as is..)It is a sure stopper in close,but does fall short of the heavier styles the further you go past 100 Yd. Great find on your rifle,and at a REALLY good price.. Onceabull

[handirifle]

Not sure about the Marlin, but the Win 94BB can be pushed pretty hard. I have achieved 2200fps with a 250grjacketed bullet from mine. More sane limits are around 2100-2150. That was RL7.

I don't think the Marlins go quite that high, but close enough so as not to matter, I'm sure.

Most guys seem happies with a 220 gr bullet around 2000fps from the 375. It is WAY more gun than the 38-55's so you are not limited by their power levels.

I'd recommend GC bullets if you want to explore the real power of the 375 Win.

[OldBob]

I have the same rifle and it likes the Lee boolit, the mould drops them at .379, I don't size them, just coat them with ALOX and shoot 'em. I have tried Lyman's 375248 @ .377 but it is too small, works good in my Marlin '93 38-55 though.

[Rocky Raab]

I use a commercial cast bullet in my Contender 375 (the company is now gone). It is a fairly soft 245-gr plain base and about the only accurate loads I could find for it is 8.0 Unique for right at 1100 fps or 6.5 RedDot at 1000 fps. Everything hotter gave "horrible groups" according to my range notes.

I only carried the lead loads for rabbits and such while elk hunting, anyway.

[45 2.1]

So, the question is ,who makes a suitable mold for this rifle? Who has worked with a rifle in this caliber, and what were your results?

My Marlin won't shoot cast thats under 0.378" well and likes 0.380" or 0.381" boolits. My rifle will also accept 38-55 brass easily. Check this link for molds that cast the right size: http://www.brp.castpics.net/

[softpoint]

Slugged my barrel today. Twice, Looks like my bore is very close to .375 With Micro groove, would .377-.378work well ,Or should I go larger?:p

[45 2.1]

Take a lead impact throat slug and see what you've got.

[softpoint]

I just slugged the bore in front of the chamber now, (about 1") still .375, then did another to the front of the throat Looks like .400 on my mike. :grin:

[runfiverun]

you measued the freebore at 400 marlin has a goofy area there, i suspect it is to lower initial pressures.

[softpoint]

Runfive,
Your right, I just looked at a drawing of the chamber dimensions, the 375 chamber shows that, the 38/55 does not:p

[stubshaft]

I used one of these for years and was suprised that the caliber didn't catch on. I used an LBT 260gr LFN and was pushing it about 2000fps with RE7. I sized my boolits at .376". Use a push through slug and make sure there is no restriction where the front of the magazine attaches to the barrel. I've had to lap that area on other Winchesters and Marlins.