Wildcatting the 7mm Rem Mag

[Marlin Junky]

I don't know where exactly to put this thread so here it goes:

Given the widespread availability of 7mm Rem Mag brass (sometimes I can find whole boxes of once fired factory cases at the range on Monday morning) can anyone find anything wrong with the idea of cutting off the 7 Mag's neck, blowing the shoulder out straight and chambering a short action M77 to a 56-57mm long .458 round? It would essentially be a .450 Hornady that uses common brass. How much would this project cost?

Thanks,
MJ

[runfiverun]

458 mag.
the sight owner gets most of my 7 and 300 win mag pick-ups for his 458 handgun.
anyways a bbl and reamer on it plus the fitting.
bbl cost is most likely the deciding factor.

[Rocky Raab]

Well, let's just say that the brass would be the cheap part, huh? LOL!

You're looking at custom dies, a custom reamer and a barrel plus gunsmithing. I think you'd be looking at a grand and a year, or thereabouts - assuming you already have a rifle with a "magnum" breechface. If not, add in that cost as well.

And you'd have a 458 WinMag Short.

[longbow]

Sounds like a .458 x 2" project or maybe a little bigger. I have some load data for .458 x 2" and I guess you could use .450 Marlin data as well or heavy .45-70 load data for Siamese Mauser or Ruger #1 depending on case volume.

Sounds like a fun project and I can't see it costing much as you should only require a barrel and chambering.

You may need to neck ream though depending on cartridge length and brass thickness so you may require a die and reamer for that.

I used to have a Siamese Mauser in .45-70 ~ quite the thumper and this would be basically a rimless version of that.

Longbow

[mpmarty]

The only "wildcatting" I've done on 7mm Mag was to neck it down to 6.5mm and voila I had a 264 Win Mag.

[Hamish]

Marlin Junky,

Your Boolit: http://castboolits.gunloads.com/showthread.php?t=137035

[Lloyd Smale]

ive used them to make 264 mag and 257 and 270 wby mag. A better idea might be to save up a 100 or so and swap or sell them and buy some brass you need.

[MBTcustom]

assuming you have the action already.
You can get an adams and bennett barrel blank in .458 cal 1-14 twist for $89.95 from http://www.midwayusa.com/product/212429/adams-and-bennett-barrel-blank-458-caliber-centerfire-f44-contour-1-in-14-twist-26-chrome-moly-in-the-white
Rent the 7mm rem mag reamer and a throating reamer for .458.
I can make you a pilot for the reamer that will track on the .458 diameter barrel. Just ream it for 7mm and then chase it with the throating reamer.
You can rent them from this outfit:http://www.reamerrentals.com/?gclid=CNXQh8LBk60CFUHRKgodI025mQ
If you have a buddy with a lathe that likes beer, you can get the barrel threaded and chambered for free, (or at least for the almighty liquid currency.)
Now for the dies, buy the 7mm Lee Loader from http://www.midwayusa.com/product/474390/lee-classic-loader-7mm-remington-magnum for $25.00
Figure up how much press fit you need on the dies and have said buddy bore it out to give you that fit.
Voila! Wildcat rifle, brass and dies for $150 and a couple cases of beer!
I have done all of this once, and I just finished the second rifle! All of which I posted detailed building instructions here an castboolits for the edification of individuals like yourself that think outside the box.
Lee Loaders are a wildcaters dream.
If you decide to start this project I would be glad to help you out with what I can.

[mellonhead]

How about a rebore and use 450 Marlin dies to load it. Probably have less than $300 in it. Just have JES rebore it and he will cut a new neck from what I understand.

Toby

[frank505]

I neck up 7 mag brass to 416 Taylor, love to leave the emptys in the hills so they wonder.........

[Sonnypie]

I entertained a similar idea once about converting 30-06 brass with neck cracks, into 45 ACP brass.
It quickly went in the trash when I discovered how thick the brass was in the lower part of the casings.
But do keep thinking. It keeps the grey matter wiggling. ;)

I did convert some 270 brass out to 30-06. A friend told me it would, and it did.

[MBTcustom]

By the way, thats an awesome video Sonny.

[Char-Gar]

Take a look at the 458 American a wildcat from yesterday. It is about what you want to do.

That aside, I don't think the availability of range pick up brass is sufficient motivation to build a wildcat rifle. You are talking about major dollars.

[Sonnypie]

By the way, thats an awesome video Sonny.

Thanks! I'm glad you liked it. :D
Isn't it just...
Magnificent! (http://www.andiesisle.com/creation/magnificent.html)