Anyone tried this yet ore have the reamer to do so?

You only need someone with a 300 Ultra reamer with removable pilot and then the 35 neck and throat is cut separately very common.

One thing you might wish to consider unless you are using a Weatherby or CZ, is to have a 35/338 Ultra instead of the 35/300 Ultra. Some of the 35 calibre bullets seated to the cannelure will give a loaded lenght that is longer than most 375 length magazines.

That is why the 338 Ultra was made slightly shorter than the 300 Ultra.

I had this problem with a 358 STA with 250 Hornadies, a bit long for either Rem 700 or M70 375.

Mike

Thanks MIke that is a simple way to do it. I have a 358 Norma which would be the same as the 35/338. I was hoping to get a little more with the added length of the RUM comfiguration due to the larger case.
Frank

I've heard that going from a 358 Norma to a 358 STA or 358 Rum results in a gain of velocity of ~200 fps, but a tremendous gain in recoil.

I've chickened out of my thoughts of building a 35 that burns more powder than my 350 Rigby. I figure the answer is either make a bigger hole, or get closer.

I have a reamer for a .358 x 404 IMP.full length.It can safely drive a 250 gr. bullet at 3100fps. Ultra mag cases are just bigger enough that they will not quite size down enough at the head. .404 cases work great.When I designed it there were no Ultra Mags. or I would have used the less expensive cases. roger

Frank

Necking up the 338 Ultra to 35 will give you a case that is only about 4 grains smaller than necking up the 300 Ultra or necking down the 375 Ultra

The actual difference might be smaller because bullets won't be seated into the case as deeply.

There is a chap on 24HourCampfire who uses the 338 Ultra necked to 7mm instead of the 7mm Ultra for the same reason.

Mike

I also have a 358-404 similar to Roger. It is mean. A 280g A-Frame, 3.6" long will go around 2930fps before I get uncomfortable. I keep it at about 2850. That's the SD of a 375 300g or a bit more. Any of these, 404 or RUM cases below 416 are pretty much overkill. But I love it.

I love it too. I have both the 338 and 375 UM. Both were horrible until I switched to the laminated stock and Limbsaver pad. They still scream for your attention when loaded max but I derive some very strange thrill when I can shoot for a while and still squeeze the trigger like when I shoot my .257 and 220 swift.
I tried all the STA's and have dropped them all save the 358. I have a thing for .358 so the UM is next. If I get another .35 barrel and switch for the .375 I will have the length and another wildcat to play with. I don't think I will experiment until I find someone able to keep it more like a RUM with the same size brass as the .375.
Frank

Well, you know John got his reamers from Pacific. You can, too. They'll make anything you want. Buy your 375 RUM cases, and decide on your shoulder/neck/throat config and send it all along with a barrel to your favorite smithy.
Or, you can work it out yourself, with Pacific's help, and send the reamer off to Douglas, Pac-Nor or whomever. Then send a few fired cases to your favorite die maker and let the games begin.

This is basically the 360 Imperial Magnum, it was sold as such some years back. 250 gr bullets at an easy 3000 fps, the thing is a real hammer. - Dan

Thanks Dan. Maybe I can find dies and brass for this one.
Frank

Dan is right it is a 360 IMP.
Just got my 1999 Montana action last week.
Did find 360 IMP dies, bought some 375 Rum Brass ran them through the sizer die,seated a 250 Horn. checked measurements to a 360 Imp round and found them to be the same loaded OAL lenght is 3.6" so it fits the Montana action

Regards Martin

Frank,
www.realguns.com did this, and an article, if i remember correctly

jeffe

Thanks Martin,
Frank Martinez

Posted 18 February 2005 05:16
Thanks for the information, I would like to know more about this round. Do you have more info you could share? Where did the dies come from?
Thanks for the help,
Frank
Jeff, I tried the link but it did not work for me. Is it still active?
Frank

I don't why but you can't link to it.

So physically type in www.realguns.com and it will open.

He has some pretty flash ballistics for the 358/378


Mike

The Imperial, or Canadian, Magnums are built on the Jeffery, which is a hair smaller than the RUM. The RUM has beec 'catted up and down by Fred Zeiglin - as I'm sure others - who calls then "Ultra Cats." Check out Z-Hat for more info.

Thanks Mike. I keep getting a SpamHIppo protection login needed but can't seem to be able to find out how to sign up for that. I used to be able to go to real guns on my other computer without problem so it must be my overly protective system or something.
I had a chance to talk with Fred at the Dallas show re: the building of a take down multi barrel but wasn't looking at that time. I will look into the Z-hat linup also.
Martin, thanks for the additional information.
Frank