.458 Win Mag on a Short Action?

[mdwest]

Someone tell me if this is within the realm of possibility.. or not.. and if it IS possible, what the potential problems would be?

Here's the deal...

I've got a M70 short action available for a "build" project..

The action started life as a WSM.. so the bolt face is already set up for a "magnum" (the WSM family of cartridges uses the .404J as the parent case).. the action rails are already set up for magnum width cartridges as well due to the .404J parent case..

I've been thinking this might be a good action to use as a foundation for a .458 win mag build (or some other shorter length big bore cartridge.. .416 taylor perhaps? or something else?)..

The issue is the magazine and action are designed to take a max COAL of 3.1"... and the .458 win mag has a COAL of 3.340.. so we're looking at things being about .24" too "short" to accommodate .458 win mag or .416 taylor..

Im wondering if a competent gunsmith could remove some metal from the front and rear of the action similar to how long action 98 mausers are made to accommodate magnum cartridges and if the magazine could be elongated a bit (similar to how @Shawn.54 worked his .404j project)..

I understand it would probably be cheaper to just go buy a .458 win mag than to rebarrel my current action and have the work we're talking about done..

Im just wondering if it is possible.. if so, it might be a fun project (the WSM isnt getting a lot of love or use lately anyway..)..

Im not too worried about pressures.. the WSM action is rated to 65,000 PSI.. assuming machining on it wouldnt weaken it much, 458 win mag produces about 53,000 PSI, and from what I can tell 416 taylor tops out at about 60,000 PSI with hot loads.. and I seriously doubt I would ever load either of those cartridges "hot"... if anything I would probably download them a little bit..

So... am I crazy? or is this something doable? or worth doing?

 

[Dinsdale]

This has all been hashed out for big bores on WSM actions with lots of good info, testing, brass, etc.....

http://sskindustries.com/bm-rifles-and-cartridges/
http://www.b-mriflesandcartridges.com/

I've shot a 500 B&M.....that shorty barrel is terrific. Like to build a 458 to play with.

 

[Gert Odendaal]

I suggest you consider the .458 African, designed by Pierre van der Walt..it is a great thought through design. See if you can get hold of African Dangerous cartridges by Pierre van der Walt...you will find all the detail in his book...all components are available if you need to build this caliber ....since this action was based on a 404 parent case , the .458 African is based on a 404 Jeffery parent case as well..so you need only to get reloading dies and a reamer...

 

[mdwest]

I googled the book, it looks like Amazon is offering a free "e" copy of it to anyone that has a subscription to KindleUnlimited: https://www.amazon.com/African-Dangerous-Game-Cartridges-Pierre-ebook/dp/B00936F5CU

I found a hard copy of the book for a reasonable price ($35) that I am ordering now... https://www.outdoorvisions.com/proddetail.php?prod=1119201204

No matter what I end up doing with this action, I think this will be a nice book to add to the library. Thanks for the note Gert!

 

[Gert Odendaal]

You are welcome... I need to complete the 3D .500 Jeffery project shortly since the second phase commenced yesterday...casting of the wax into steel items...here are two photos:
Step 1 :
Wax silicon casts on the tree:

The first undercoat /primer layer on ..ready to move to the slurry bath...

I still need to build my 8x68S hunting rifle ..then if I have the time and resources I really want to build the .458 African...

 

[CTDolan]

I googled the book, it looks like Amazon is offering a free "e" copy of it to anyone that has a subscription to KindleUnlimited: https://www.amazon.com/African-Dangerous-Game-Cartridges-Pierre-ebook/dp/B00936F5CU

I found a hard copy of the book for a reasonable price ($35) that I am ordering now... https://www.outdoorvisions.com/proddetail.php?prod=1119201204

No matter what I end up doing with this action, I think this will be a nice book to add to the library. Thanks for the note Gert!

It’s a great book. The Kindle version is okay but there’s a lot of content really only usable via the print version.

 

[CTDolan]

By the way, the 458 African is a good cartridge, kind of to the .458 family of cartridges what the 416 Ruger is to the .416 family of cartridges.

 

[mdwest]

Im trying to find a reference to the .458 African COAL, but cant seem to find one..

Can someone confirm that it will fit in a short action (COAL is 3" or less?).

Ive found a few references where people have used standard long actions like a 98 mauser or a long action M70 to build a .458 African.. but havent found a reference where a short action has been used..

Cant seem to find anyone with reloading dies or a reamer either.. but.. I've just begun the search

 

[mdwest]

Answered my own question(s) and found a reference on COAL.. it looks like its 3.40".. which would make it too long for a short action without doing some pretty significant work to the action...

I might be better off just re-barreling to .325 WSM.. not that I think I would have a whole lot of use for a .325 WSM.. but.. at least it would be something "different"... I currently have more "deer" rifle calibers in the safe than I know what to do with.. a .325 WSM might make a good PG rifle for the big/tougher critters, as well as a good bear/moose/buffalo (water/asian, not cape..) gun...

 

[CTDolan]

Yeah, the 458 African is definitely not a cartridge with an overall length of less than 3". Sorry, I would've mentioned it had I known that you're trying to stay within such a length (had I read the thread top to bottom prior to typing).

 

[CTDolan]

To answer your original question of whether a short action can be opened up to accommodate something such as a 458 Win Mag or 416 Taylor, the answer is yes. The smith will need to know what they're doing, though, as not doing it right will introduce a whole host of issues (from feeding to safety).

 

[IvW]

Sell the action and buy something you can build a proper DG rifle with.

 

[mdwest]

Sell the action and buy something you can build a proper DG rifle with.

Selling or rebarreling into something else that is more PG or "domestic" hunting suitable will likely end up being the decision made..

I've got a .375 H&H currently, and a 98 Mauser action that is in the process of being built into a .458 win mag that will serve as my DG arsenal..

The idea with the M70 WSM action was to have something to tinker around in the garage with on a build project, learn a few things, have fun, and hopefully when it was all done take to the range and play with.. Hunting something with sharp teeth, claws or a particularly bad attitude with it isnt really a consideration..

 

[fsrmg1]

I think that about the biggest you'll get in a short action with some grunt is the 450 Marlin, unless you want something obscure.

 

[Wheels]

Can you do a 458 B&M and have a short action 458?

@PHOENIX PHIL might could add to this conversation.

 

[PHOENIX PHIL]

Can you do a 458 B&M and have a short action 458?

@PHOENIX PHIL might could add to this conversation.

The .458B&M is a .300RUM cut down to WSM length action. Slightly longer than typical short action.

 

[PHOENIX PHIL]

Someone tell me if this is within the realm of possibility.. or not.. and if it IS possible, what the potential problems would be?

Here's the deal...

I've got a M70 short action available for a "build" project..

The action started life as a WSM.. so the bolt face is already set up for a "magnum" (the WSM family of cartridges uses the .404J as the parent case).. the action rails are already set up for magnum width cartridges as well due to the .404J parent case..

I've been thinking this might be a good action to use as a foundation for a .458 win mag build (or some other shorter length big bore cartridge.. .416 taylor perhaps? or something else?)..

The issue is the magazine and action are designed to take a max COAL of 3.1"... and the .458 win mag has a COAL of 3.340.. so we're looking at things being about .24" too "short" to accommodate .458 win mag or .416 taylor..

Im wondering if a competent gunsmith could remove some metal from the front and rear of the action similar to how long action 98 mausers are made to accommodate magnum cartridges and if the magazine could be elongated a bit (similar to how @Shawn.54 worked his .404j project)..

I understand it would probably be cheaper to just go buy a .458 win mag than to rebarrel my current action and have the work we're talking about done..

Im just wondering if it is possible.. if so, it might be a fun project (the WSM isnt getting a lot of love or use lately anyway..)..

Im not too worried about pressures.. the WSM action is rated to 65,000 PSI.. assuming machining on it wouldnt weaken it much, 458 win mag produces about 53,000 PSI, and from what I can tell 416 taylor tops out at about 60,000 PSI with hot loads.. and I seriously doubt I would ever load either of those cartridges "hot"... if anything I would probably download them a little bit..

So... am I crazy? or is this something doable? or worth doing?

Dave a link to B&M rifles:
http://m.b-mriflesandcartridges.com/458-B-M.html

And a link to the story on mine:
https://www.africahunting.com/threads/458-b-m.11420/

 

[Wheels]

The .458B&M is a .300RUM cut down to WSM length action. Slightly longer than typical short action.

Does the action have to be modified? I guess I thought the idea of the B&M was to fit in a short action.

 

[PHOENIX PHIL]

Does the action have to be modified? I guess I thought the idea of the B&M was to fit in a short action.

As I remember it does not require modification. Take a WSM action and mate it with a new barrel. Find .300RUM brass and cut to 2.24". The modified brass can then be put through a sizing die that can be ordered from Hornady and you now have one of the B&M calibers.

 

[AZDAVE]

X2 for Phil's 458B&M recommendation. I own one because of Phil and he says I am a bad influence

It is a 300 RUM brass cut down has almost the same exact powder capacity as a 458 WM. (404 Jeff is thee base brass for what the RUM was developed from) (You can also use any of the RUM brass and cut to size) The B&M site has all the info you would need to make a decision with.

The action rails are set up already and don't require modification, and mine feeds any bullet shape that I have tried IE Spire point, hollow points and CEB and Northfork cupped solids from 300-480gr bullets. I settled on the barnes 300gr SOCOM bullet for my Alaska rifle. But it also shoots the 480 level softs and solids to the same POI and would happily use it on a cape buff. (But my DG rifles are doubles)