From the left .300Win Mag , .350 Express and the .350Rem Mag

I am a 358 Norma fan and the wildcat you are looking at looks pretty good. With a tapered expanding plug making your cases would be a snap.

I generally make my Norma from 300 Win or 8mmRem and need to do a bit of trimming which you can bypass.

Also might get another 50-100ft/sec with the slightly increased capacity.

One caution is I would use a long action since 35 bullets do take up a lot of case capacity and the 300 Win is a bit long for a standard action.

That does look like a good round. But that one in the picture would take a 375 h-h length action. The normal 300 win mag takes up all the room in a standard action.

That looks like a dandy cartridge a big 35 will do it all. Take care. opening the neck and fireform with fast powder and cheap bullets. I opened up the 300 a little further to the 425 Express and my 358 is a Norma. Good Luck

I plan on building it on my Winchester mod.-70 300Win Mag. The .350 Express cases fit in the magazine even with the long 225gr NBT.

Its a350 Jacob
This a homespun 358/300 Win. Mag. wildcat varient. It has only been chambered in two rifles as of this writing. The developer is a gunsmith who lives and works in Montana. He uses 225 Sierras (he tells me because he has a fairly large supply of them on hand) and has reached 3200fps with those bullets so far. It's case capacity is 84 grains of water and is FAR MORE EFFICIENT than the 358/378 above - though it just about matches its velocity with 225s. I'm told the short neck has not been a problem (as per the 300 Win.Mag. parent case itself). The cartridge is named after the cartridge creator's son, who now is the proud owner of rifle # 2 himself - an engraved custom Winchester 70. How cool is that?

Further details on this cat will be forthcoming when I can find time to post morelready been done

Sorry guys , the cut and paste thing got kinda scrambled on me. What I was trying to do was give you the link to Whelens 35 wildcat page and let you know that someone has already necked up a 300 win mag to .358
Dave

I found the link you are talking about...but that 358/300 is blown out and improved. That's a cool looking case though.

Another one recently talked about on another forum is a 300 WSM (short Mag) necked up to .358.
Interesting although I'm not a short mag, ultra mag fan due to the lack of magazine room, give me a 30/06, 35 Whelen or a 375 H&H any time.

T/C Nut

What is wrong with 358 Norma Magnum or 358 STA?

Cheers
/JOHAN

Nothing is wrong with those. I just want to be different. Wanted something that was easy to form and cheap brass.

Go for it T/C Nut, and be sure to post how it works out for you,
BD

You could go the easy route and be able to seat to the lands in a standard length action and get the same ballistics and go with the .358 Norma Magnum you know.

Should be plenty potent.
Couple of comments:
What's the chamber going to look like? With long bullets seated out, you'll have to jump with sgort, light bullets.
If it's anywhere near 3.6" withe the heavies, and that's what you plan shooting, it should closely rival the STA with a bit less powder.
Kinda funny - Win makes 338, Norma necks to 300 & 358 (no one buys) Win moves neck up, makes 300, now you're necking that to 358. Norma's going to be mad!

How about shortening a 300RUM some and then opening to .35? Could you then get away with a standard length action and have the same case capacity as the 350Express? Personally, for ease of loading I'd rather a 358Norma, custom reamers and custom dies are costly. Mind you I think you could load the 350Express using a combination of other dies. Just my thoughts.
Cheers...
Con

T/C Nut

It's very easy to make 358 norma brass from 7mm rem, 300 win or 338 winchester.

Cheers
/JOHAN