Can anybody tell me if this is possible or has it already done ?
Was looking in my Speer manual and just got to thinking. So many calibers have been made by either necking up or down cases and re-chamber.

Was thinking of a 338 necked up to a 358 caliber and then a standard magnum receiver could be used. This what I looked at for the thought process.

358 Norma Mag
max case length 2.520
trim 2.510
max cartridge length 3.400
velocity 180gr Speer bullet 3000+ fps


338 - 06
max case 2.494
trim 2.484
max cartridge length 3.340
velocity 200gr bullet 2700+

338
max case 2.500
trim 2.490
max cartridge length 3.340
velocity 2900+ 200gr bullet

Since the 358 Norma is a longer max cartridge length with the bullet seated, would it fit in a standard mag box magazine ? Would it be easyto re-bore a 338 and re-chamber or just have another barrel made ? Brass is plenty and easy to find for the 338 and I guess a company would have to make a set of dies to neck up a 338 to 358 caliber. If anybody owns a 338, would you step in and tell me what the max box magazine would hold for loaded round. Is there room for extra max cartridge length 358 Norma mag.

Thanks. Just something to chat about.

Ken

That mind of yours just never rests when it comes to 35's, does it?

I wonder what made you say that !

What are you expecting to get over a .358 Norma? Two hundreths of an inch shorter case length, six hundreths OAL, when most standard magnum length actions already will take the .358NM, not to mention longer rounds. I'm not trying to come off like a know-it-all (which I assuredly am not) but what's the point? Seems like splitting hairs for not much gain.

358Norma brass is easily made fron 300WM,in fact if you leave the case 300WM lenght,you get a real proper looking case.

I'd step right up to 375 Ruger, but I'm a 3/8s bore guy through and through.

I suppose you could neck up a 338 win mag to 358. You might be able to fudge on not having to have a reamer made as well. 338 win mag for body and 35 Whelen for neck and throat. I had a 375 taylor done this way with a 338 for body and 375 H and H for neck and throat. I am speculating, haven't looked carefully at whelen dimensions.

The dies will kill you. Redding made the 375 taylor and it was approx $140 IIRC.

I would suggest you either go with a 358 Norma or 375 Ruger if saving money is a concern.

KDK - What are you expecting to get over a .358 Norma? Two hundreths of an inch shorter case length, six hundreths OAL, when most standard magnum length actions already will take the .358NM, not to mention longer rounds. I'm not trying to come off like a know-it-all (which I assuredly am not) but what's the point? Seems like splitting hairs for not much gain.

KDK, I just posted a bunch of questions for thought. I'm not looking to gain any more velocity or power. I'm just looking for answers for a build. 358 Norma Mag brass does seem to be readily available. I didn't know if the 358 Norma Mag loaded ammo would fit in a standard magnum box magazine or not since it's just a bit longer. I went with the 338 because the bolt face wouldn't need any special work. I'm a 35 caliber guy and that's why I chose the 358 mag. I'm looking for ideas for this build. I figured that I could find a 338 donor receiver and work from there. Thanks for the info and thoughts and keep them coming.

Ken

Ken,

If you are in an experimental mood, I have a set of .350 Ackley short mag dies, I'd be more than happy to loan you for experimental purposes.... Or sell you for that matter....

I have looked in all my library for specs on it and I can't find any. But I believe that is exactly what these dies are. Perhaps with a slightly different shoulder angle?

I've often thought about building one just for conversational purposes...

Grasshopper

I think that was called the 35 Belted Newton depending on exact length. The 358 Norma should have done better than it did. I would use the 375 Ruger case either as is or re-create the 35 Newton.

35/300WM is good too, then there is the 35 G&H, 350 Rigby, Mashburn, Gibbs, Brown/Whelen lots of possibilities.

Boston

I have an original .35 Newton. And I make my cases out of .375 Ruger. I suspect you are right on the .35 Belted Newton...

Grasshoppper

i don't see any reason why the Norma Mag shouldn't work in a Standard mag box. mine is built off of a 1903 Springfield, and a i've seen a lot that where just surplus 98's. for most of my brass all i use is fire formed .338 WM, no need to trim after resizing, and is only a little bit shorter.

How about using the 300 win mag case?
Now that the wsm & the ultra have hit the scene the racks are full of winnies. I guess it would be the 35 Express

Why not neck the 375 ruger down to 358?

Some really good suggestions and ideas. Time to find a donor action.

Ken

You got it right, Kevin!

Ted

I understand, you're a 358 guy and you want something different. The most practical would be the 358 Norma it has good headstamped brass available and it will fit a standard 3.4" magazine. All short belted mags (300W, 338W, 458W, etc)are suppose to accept the 3.4" AOL, some easily (Sako) and some are tight. These will fit your magnum action.

I've made just the 338 W necked up to 358 and 375, still have the Manson reamers and Redding dies but sold them or made the rifles into something else. I've also done the 300 mag case with some slight modifications to various calibers (neckage?) from .323" to .411" and have that hardware too. That may require neck reaming as I pushed the shoulder back on that one.

The 338-06 and the 35 Whelen the share the '06 case and won't fit your magnum bolt. Both are quite useful within their capability but they won't be magnums.

I have to wonder about your ballistic expectations. Why a 180 grain bullet in a 35 caliber mag? If you want 180 grains stick with 30 caliber. You give a nice prairie dog log there for your 35 super mag dreamer?? There is nothing to be gained with the 338/358 when we go to 180-200 grain bullets just to get that crack from extra velocity.

358 STA

358STA needs a H&H lenght action.