375 Win Super Short Mag

[mcwoodduck]

Hello,
I had a strange Idea while reading another post in the big bore section and wanted to know if any of you have played with cutting the belted mag down to 308 length or even 450marlinnd necking it to 375.  I'm not looking for 375H&H  speeds but more like 375 Win out of a bolt action rather than a lever with the ability to go from 235 grains to 300.
I figure I would just use the necking from 375 H&H on the short case and screw my 375 H&H dies down to 308 length to reload.
Any information would be helpful.  I'm thinking of a new 98 mauser project.
McDuck

[bull]

I had some wierd ideas like that after getting my hands on a set of .375JDJ dies and playing for a while. Belted mag cases are expensive though.  But the one interesting thought that I did have was running a 8x57mauser case through the .375JDJ dies. Length is about the same, and the body dia. is about equal, other than taper. I thought that this setup could make a nice bolt rifle cartridge. But then my wife says I spend too much time at the loading bench.

bull

[mcwoodduck]

Bull,
     If it were not guys like you playing at the reloading bench we would not have rounds like 257 Roberts, 7-08, 7mm Remington Mag, 35 Whelen, or any of the JDJ stuff.  But go spend some time with her so she doesn't end up with half your reloading equipment.
     My other question is how do I work up a load with out blowing up the gun?  In the Mag case what is the min and what would be the max if I cut the case down and neck it the same as .375H&H (as I have the dies already).  Would a charge of 50 grains of 748 with a 300 grain bullet produce too much pressure and ruin more that the gun?  Would a load for 375 Win or JDJ be too much for the belted case.  there is that whole school of internal ballistics that I do not know about.  You know like how 22 PPC using a charge of the same powder will throw the same weight bullet faster than out of a 223 case.
     I'm not too worried about the cost of brass.  I have a 338 Win and a 375H&H as well as friends with 257 Weatherby, 7mm Mag and 338 Win and as they reload the cases more than 10 times they tend to throw away the cases rather than trim the hot mags.  but these tossed cases could be cut and renecked to make the new short rounds. 
     Again this is just thinking of a round to make for a 98 action project.  I'm thinking of a 20" tube with a full stock, no sights and a Trijicon 1.25-4X28 scope.  308 win, 338 fed, or 358 Win was my first thoughts of a heavy brush gun and reading the posts about 375 Win got me thinking about something in the 375 bore.  I know necking 308 /30-06 to 375 does not leave much of a shoulder and the rimless rounds need a shoulder to head space.  So I started thinking about the belted stuff and why not ask the group of pros here if any have done this.

[iiranger]

#1). Mr. Ackley, in his books, reports on a rimless .38/40. The .30/'06 case was cut off so it headspaced on the mouth, alla .30 Carbine or .45 ACP, loaded to the .38/40 power levels (.40 Cal bullet) and it single stacked in the double stack magazines of the .30 Carbine... Large "pop" gun...

#2). You will be getting back into the body brass big time. Fun with form dies and a heavy press. Imperial Wax? or Lanolin? Corbins make the heaviest presses, leverage wise.  No doubt you will have much brass shavings from neck reaming. Can be done but it is work, unless you are really enjoying... Once you have your case, measure capacity... fill with water, weight water, convert to "cc"s ... Lee lists "cc" capacities in his load manual. I would cut any load for a similar bore/cc capacity by at least 10%, but that should be pretty safe. luck.

[bull]

McWoodDuck,

Don't worry, the Mrs. and I are all in good standings. She just cant see what I see when I start rolling a brass case around in my fingers. And no, I'm no Ackley or anything like that, I think I'm half a century too late. Most, if not all of what I dream up has been done. But, like you, I am thinking of a fairly large bore cartridge, not too heavy on the recoil, that would fit in say a surplus mauser action. I mentioned the 8x57 only because the length matches the length of the 375JDJ that I just started playing with. And I think that if the taper was blown out a little, there should be just enough of a shoulder. No worse than a 375Whelan anyway.

bull

[mcwoodduck]

Bull,
  Ok, that may be the answer. But is the internal case size the same as the 444 marlin case that the JDJ is made from?  If i went that way, I think I would use either the 308 case or the 30-06 case as I have a bunch but fo not have a lot if any 7mm or 8mm brass anymore.
If I do find some 8mm brass.  I think I have some from Remington.  and maybe some 7mm by Federal. Do you want it?  I just moved from Southern CA to Northern and as I am unpacking and setting up my reloading section in the garage I'm finding all kinds of cool stuff.
I may have a huge list on Pay it forward.
McDuck

[bull]

McWoodduck,

Since you keep feeding my imagination, I made up a case from a 30-06. Trimmed it down to 2.230", which is real close to the length of the .375JDJ, then ran it through the JDJ sizing die. Powder capacity was almost exactly identical to the .375JDJ. And it looks like it might even feed through the mauser feed lips without too much change. I'll have to see about that yet. I used a cut down 30-06 case only because it more closely resembled the taper of the 375JDJ, where the 8x57 has more taper. Of course if I were to ever get my rifle sent off to SSK for rechambering, I would have a better idea of the exact capacity of fire formed 375JDJ rounds. I have a Ruger #3 in .375 Win that is going to be converted to the JDJ round. And I think that a semi-rimmed version in a bolt action would be just that much better than the overly publicized .338 Federal. Much like a 9x57 mauser would be.

bull

[mcwoodduck]

Agreed.
Sounds like a great project.
I was thiniking the same thoughts only slighlty one off.  I'm now looking at a 9.3X62 Mauser but opening it up from .366 to .375.
Depending on what the original caliber of the 98 action was as to what stripper clips will work.  The 7mm stripper clips are what the US army uses when you buy surplus 06 or 308.  they also work in the Springfield or the M1A.
The 8mm stripper clip is just a little smaller and the 7's will not work in the 8's, and the 8's are a little wobbly in the 7's.
Both strippers will work with the 473 back end that 7X57, 8X57, 308, and 30-06 all share.
If I can find the 8mm brass I have do you want it?
It's remington and once fired.

[bull]

9.3 sounds interesting also. Too bad there aren't more choices in bullet selection. From what I've read on the 375 Whelan, it woul be best to go with the improved version, a little less taper, and a little more shoulder. Or just go to the 375 Hawk/Scoville. I already have a nice old sporterized Gew98 chambered in 8mm-06 That I love to hunt with.

As far as the brass, I'd be willing to take it off your hands. Let me know what you want for it, shipping and all. I'm in michigan.

bull

[mcwoodduck]

Bull,
PM me your address and when I'm out in the garage next week.  I'll sent it to you.  i need to find it first.  It's probabally only about 100 or so.

[Smokin Joe]

McDuck, using the .350 Remington Mag case expanded to .375 will solve quite a few problems.

[mcwoodduck]

Oh yea,
I forgot about the .350 Remington.  That would be easier as a starting point.
I guess I should change the name of this to .375 Remington.

[NFG]

What you are talking about has been done several times already.  I suggest picking up "Wildcats of the World" or "Donnellys Manual of conversions" and "Load from a Disk" or "QuickLoad" before you get too involved in your conversions.  No use in reinventing the wheel after it's been reinvented a bunch of times.  Your basically talking about a 350 WM necked up to 9.3 or 9.5(375) cals.  Both are simple, easy conversions and dies can be had at a reasonable price.

Ch4D has dies for a 375/450 Marlin and PT&G will make you a reamer.  There is also the 357 Taylor or the 375'06, 375 Whelen or Scoville that will work great in the M98 and don't forget the 9.3 x62.

8x57 cases make fine 375 JDJ replacements, but cutting the belt off a belted mag case is just a lot of work for no gain and hasn't been done for 30 odd years that I've heard of and even then only for specialized applications.  Just use a WSM case instead or a 375 Ruger case, a Jefferys case...or any number of other cases.

I just did a 9.3x62 in a VZ-24...nothing but a barrel change and the usual M98 mods.

'Catting was one thing 40 years ago, but is a cat of a different color in today's world...you need to study up on it well before deciding...unless you're just sitting around the campfire in amongst the whiskey fumes and having a good bit of fun blowing smoke.

I have a set of hardly used 375 JDJ Redding dies, a bunch of 444 M and 8x57 cases and a lot of data I will sell if anyone is really interested in doing one.  I had plans on doing the JDJ but ended up doing a 458 WM instead.

[no.country]

Have you thought about a 375/284 it has been done and dies are available.
Cheers No.country

[brasskeeper]

375/350rem mag sounds interesting, but I bet that brass isnt cheap.

[NFG]

350 RM brass is fairly cheap and available and it can be made out of just about any mag case.  375/350 RM is basically a shortened 375 Taylor.  Would work well in SA actions...Problem was everyone wants more pizzazz therefore longer and larger cases.  Nowadays the trend seems to be toward shorter, fatter cases to get case capacity  in SA's.

Both cases produce excellent ballistics.  The 375/284 is prime for a Sav 99 conversion.   Just about as large as the rotary mag can handle and very nice case capacity...several have been done...takes a bit of mill and lathe work and knowledge of the gun to get it to work right.    ML McPherson's "Accurizing the
Factory Rifle" has some information on a conversion to his 375-284 Mac, slightly blown out version or the 284 case.  It also include a section on how to accurize the Sav 99.

[no.country]

NFG I have a question on the 284/375 in the 99. would it be easier to use a gun that had a box (clip) mag. as no
mod to the rotor mag needed just the lips of a clip for a 308 as mag.'s for the 284 are hard to come by!
Cheers no.c