Has anybody had any experience with a 358 RUM? I had seen it listed on the Virgin Valley web page and thought it looked interesting. They don't seem to know anything about it. I would imagine that it is the 375 RUM necked down but only a guess. I have a Ruger #1 action that needs a caliber and was leaning toward a 358 STA however my envelope is 338-375.

There are two 358 RUMs,

One is based on the 338 RUM and the other is on either the 300 or 375 RUM.

The 338 RUM is about 1/10" shorter so that 338 bullets when seated to their cannelure give an overall lenghth that is OK for the 3.6" M70 and 3.65" magazine of the Rem 700.

In the 35 calibre, if bullets such as the 250 grain Hornady are seated to the cannlure then the full length 375 RUM case will result in a cartridge that is a bit long for M70 and Rem 700.

Of course none of this is an issue in the Ruger 1. However, you might fall in love with a 358 RUM and want a bolt action. In that case it would be better if you had setup initially around the 338 RUM case.

I have had three barrels in 358 STA. In Australia the 35 calibre is better than either 338 or 375 if you want to play around a lot. The reason is that the barrels in 35 calibre are available in twists of 1 in 12, 14, 16 and 18 and groove diameters of .356, .357 and .358. It maybe different in America. The reason we have all the variation in 358 as compared to 338 and 375 is because of the different rifling buttons and barrel reamers for the 35 calibre pistols.

Mike

Mike375
Thanks for the Info. Looks like I have a few choices in the 358RUM. You have a good point about going with the 338 based version. What type of ballistics are you getting from the 358STA for a 225 or 250 gr. bullet?

Look around the web and you'll see some pretty impressive data for the STA. That's usually loaded pretty hot. Expect a little better with the RUM, and not so hot, or as hot and another 100 fps.
I'm loving the 35 caliber more and more. Strange as it is that it's fallen into obscutriy, it is and excellent "big medium bore" and has it's place right inbetween the 338's and 375's.
I think the brush-buster reputation, deserved or not, led to it's denigration as the mythical 500yd shots and the magnum high-BC loads that made them came into vogue.

I already have a 35Whelan Imp(My Whimp gun) and get about 3900-4000 Ft/lbs from a 225 gr bullet. I would like to jump another 800-1000ft/lbs. Sounds like either of them will do the job. I will have to scout around a bit for some more reloading info on the 358 STA. Your are correct about 35's getting a bad rap which is too bad.

Quinn, i have a .358 Griffin & Howe Imp. which is the same as the STA. I get 3175fps with the 225 and 2950fps with the 250NP. It also likes the 280 Swift at 2800fps. I have a buddy who built a .35 useing the .375 Dakota case necked down. Good luck with your .358RUM

Quinn

From memory the 250 grain Hornadys went around 3050 and 225s were at something over 3100.

Mike

Call it what you will ; my wildcat .358X404 improved is within a gnat's whisker of what you are talking about. It has safely pushed a 250 gr. bullet OVER 3125 ft./sec.(measured) roger

Check these loads from 358/378 Wby

http://www.realguns.com/loads/358378.htm

Big Power

Mike

Mike375, that is an IMPRESSIVE round you got there

Quinn, the 358 Rum would be the same as a .360 Imperial.
There where 4 cartridges (I believe) the .311 the 338 the .360 and the .375 they all used the same cases.
I compared the dim. and they are the same as as the RUM cart. exept for the 300 RUM
I found a gunsmith that still has a 360 reamer and also found a die set.
Bought 100 375 RUM brass and resized them in the 360 dies,works perfect.
So I am waiting for my Montana action to build the gun.
On the other hand I have a 340 with a fancy octagon barrel with some pitting in it maybe it would be smarter to rebore and rechamber for the 358 RUM /360 Imp. and use the action for a new 340.
decisions,decisions.

Regards Martin

Mike375
I have seen that web site before for the 378Wby necked down. That is one impressive cartridge. It looks like the 358STA or 358RUM will suffice. By the time you get the reamers and weatherby brass you would have a lot invested in it. I looked at the dimensions like you were talking about and see that the 338RUM is shorter. I thought they were all the same.

There are quite a few more 358 options than I realized. I really appreciate all of the information that I have gotten so far.

Mark Bansner built a 358 on the RUMs for Bryce Towsley a few years ago. I built/had built a 358STA this year. While learning some gunsmithing, I also was learning to reload. I can get 225 NP to 3100 fps without really ringing things out. Accuracy has been 1/2MOA. My rifle is a 700 ADL with a 24" Douglas 1:12 twist.
Lots of good info on the STA on the web and on paper. I have the Simpson article scanned and could send them to you if interested.

ScottinPA
I would like to see the article that you are talking about. Could you send it to me at quinnmccarthy@boisepaper.com . Thanks.