Re-chambering .358 Norma Mag to .358 STA

[Death Ray 7]

I have a line (at a great price) on a Pre-64 Model 70 that somebody has rechambered (and re-barreled) to .358 Norma Mag

My question is: How hard would it be to re-chamber to .358 STA?

They both use the same rime thickness (.048).
They're both belted magnums using a rebated rim.
The head dia. of the .358STA is only .005 larger (.508 to .513).
The shoulder dia. of the STA is only .007 larger.

Is it just a matter of re-cutting the chamber?

I'm hoping one of the Gunsmith Gurus will lend their expertise.

 

[Death Ray 7]

Okay, now I'm really screwed up. Reloadersnest listed a totally different set of spec's for the .358 Norma Mag. than what's listed in "Cartridges of the World".

I'm still interested in having the question answered.
And can anybody tell me which ste of spec's is correct?

 

[royinidaho]

Not to divert but....

i have a neighbor that has a pre-64 70 in 358 Norma.

Of his 375 H&H, 358 Norma and 308 Norma, the 358 is his go to gun for elk.

My question would be "why would you want to rechamber a 358 Norma?"

 

[Death Ray 7]

Just improved ballistics.

I'm probably moving to Alaska soon and would like a little extra ooomph in my big bear gun. Looks like an extra 150fps in every bullet weight. Mostly interested in the 280gr A-Frames.

 

[royinidaho]

Whatever helps you with your confidence in the cartridge in the case of big bear is a good thing.

I'd recommend emailing any of the rifle smiths on this board as their experience is broad enough to include the finer points such as potential magazine and cartridge feeding considerations.

Also, if moving "soon' and you wish to use one of the fellas here you had best get in the que quickly. /ubbthreads/images/graemlins/wink.gif

 

[Death Ray 7]

I'm taking a .35 Whelen as my back-up rifle to Newfoundland this fall on my moose hunt. Was hoping for something with a little more oomph. My primary is a .375RUM (that I deer hunt with every year using 270gr hornady soft points) and I enjoy shooting it.

I guess for me oddball calibers are just like potato chips, you can't have just one. Having a .358Norma Mag would be great (and it's on my list of calibers to own), but it's lower on my list than the .358STA

By the way, my user name "Deathray7" refers to my 7mmSTW that I've owned for years. So I'm a huge STE/STW/STA fan. I've even toyed with the idea of a 9.3STDG (Shooting Times Dangerous Game). There are some great bullets out there for the 9.3mm crowd with extremely high sectional densities.

Back to the .375RUM; I would love to see some kind of high-ballistic coefficient match type bullets for this caliber (along the lines of the .388 300gr SMK)