# 7mag to 7mm STW?



## decoydog (May 12, 2009)

Ok, My ignorance may show here, but I would like to know what the difference is between, 7mm Mag, and 7mm STW. I assume they are .284 cal. Same cal. as 280 and 280 AI, Correct? Now the reason Im asking is I was wondering if a 7 mag action can be converted to 7mm STW


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## Rustyaxecamp (Mar 1, 2005)

yes a 7mm rem mag action will hold a 7mm STW.

Both are 7mm

The 7mm STW is a 8mm Rem Mag necked down to 7mm.

OAL for the STW is 3.6" vs 3.29" for the 7mm Rem Mag.

STW is faster than the Rem Mag. by about 200 fps (IIRC)

Brass is hard to find and pricey unless you fire form your own.


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## griffondog (Dec 27, 2005)

http://www.rifleshootermag.com/ammunition/7mmstw_071207/

Griff


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## 8iowa (Jan 28, 2008)

Rechambering a 7mm Rem Mag bolt action rifle into 7mm STW presents some serious and expensive problems. The STW requires a full length magnum action. It can be done, but most gunsmiths would probably advise against it.

With a single shot rifle, like the Ruger #1, this would be a relatively straight forward conversion. Even a #1 chambered for a different belted magnum cartridge could be rebarrelled at reasonable cost.


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## decoydog (May 12, 2009)

Thanks, I've learned something today any that's always good.


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## jmoser (Sep 11, 2002)

8iowa said:


> Rechambering a 7mm Rem Mag bolt action rifle into 7mm STW presents some serious and expensive problems. The STW requires a full length magnum action. It can be done, but most gunsmiths would probably advise against it.
> 
> With a single shot rifle, like the Ruger #1, this would be a relatively straight forward conversion. Even a #1 chambered for a different belted magnum cartridge could be rebarrelled at reasonable cost.


Not sure I follow this - the 7mm Rem mag is already built on magnum length actions, no? As long as the bolt face is the same dia [or can be enlarged] setting back / rechambering the bbl should be all that is needed?

Only the RUMs require the longer action if not mistaken?


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## thelastlemming (Sep 11, 2009)

Seems pretty well covered, but yes a 7mm is the same as a 284 caliber. IMHO a 7mm rem mag is about the ideal balance between powder capacity and bore diameter.


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## Rustyaxecamp (Mar 1, 2005)

bolt face will work for both Rem Mag and STW. Both are .532


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## Swamp Monster (Jan 11, 2002)

jmoser said:


> Not sure I follow this - the 7mm Rem mag is already built on magnum length actions, no? As long as the bolt face is the same dia [or can be enlarged] setting back / rechambering the bbl should be all that is needed?
> 
> Only the RUMs require the longer action if not mistaken?


 The 7mm Rem mag along with the .300 Win Mag and .338 WinMag/.264 WinMag all use a standard length long actions. The 8mm Rem mag that the 7stw is built upon takes a 'Magnum" length action like the original .300 H&H mag and the 375 H&H. According to the cartrodge originator however, rechambering from 7mmRem mag is possible. Here is an article about this cartridge straight from the horses mouth. 

I have lost count of those who have taken the time to write through the years to tell me how pleased they are with the accuracy of their rifles in 7mm STW. Many of the rifles had been rechambered from 7mm Remington Magnum, and the accuracy of a very large percentage improved dramatically after their rechamber jobs. 
http://www.rifleshootermag.com/ammunition/7mmstw_071207/index2.html


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## jmoser (Sep 11, 2002)

Swamp Monster said:


> The 7mm Rem mag along with the .300 Win Mag and .338 WinMag/.264 WinMag all use a standard length long actions. The 8mm Rem mag that the 7stw is built upon takes a 'Magnum" length action like the original .300 H&H mag and the 375 H&H. http://www.rifleshootermag.com/ammunition/7mmstw_071207/index2.html


OK - thanks for clarifying. My 7 mag A-bolt is the only long action bolt rifle I own so nothing to compare to; I thought the 7mm/.300/.338 mags all used magnum length receivers but I stand corrected!


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