View Full Version : .458x2 mauser

March 4, 2012, 04:35 PM
im interested in building a .458x2 rifle on a mauser action do i have to do this with a large ring reciver or can i use the small ring spanish mauser ? also if any one has built one of these rifles, where did you find your barrel is there an inexpensive barrel out there like hart and adams or am i forced to go krieger ? for my blank im not bulding a sniper rifle i just want good 1 and 1/2 to 2 inch groups at 100 yards and 300 yard capability out of it. also has any one shot this cartrige? how does it compaire to 30/30 and statndard mauser 7x57? recoil wise how heavy should this rifle be ? just in the research phase of this project any help is aprreceated

March 4, 2012, 04:44 PM
Not sure exactly what you're referring to as the Spanish Mauser, but if you mean the '93, '95, and '96 type actions then no don't do it. The cartridge would be OK in the '98 type. You might have to do some engineering to get the case to feed. Goatwhiskers

March 4, 2012, 04:52 PM
yes i was meaning the 93 action is it a matter of size or pressure limitation, its my understanding that the .458 is a low pressuere cartige as compared to the 7x57? also is does any one know where i can find the info to check that statement?

March 4, 2012, 07:02 PM
I did one that I called a 45-06 on a large ring. I opted for the .451 diameter of the 45acp mostly because I already have a supply of 300gr XTP bullets in that size and I already had a 45acp reamer that I was able to use to cut the chamber. I used a barrel blank from Green Mountain barrels and cut the chamber so that it uses brass trimmed to 2.48 inches and I load them to a COAL of an even 3.000". I make the brass out of 30-06 brass (takes a couple of anneals in the expansion process), and I am still working things up on it, but it seems pretty reasonable at this point. Before someone even asks why I made this one, I've already made the other things that interested me and this one sounded fun and cost me next to nothing to do but the time ... and the time was 90% entertainment and 10% educational :p I'm sure it will make an authoritative hog gun (every post needs some rationalization in it, right?).

There are clearly more options for bullets in the .458 size ... but then, I don't know if anyone like Green Mountain makes a 458 barrel that is reasonably priced for a 150yd gun where 0.5MOA isn't an absolute necessity.

Stay safe and I'd second the opinion of sticking with the large ring Mauser actions on this one.


March 4, 2012, 07:13 PM
My version of QuickLoad lists the 458x2 American at 59,987 psi (NOT a low pressure round) compared to the 7x57 at either 51,000 psi (per SAAMI) or 56,564 psi (per CIP) BUT the base of the 458 case is much larger in diameter so there is more area for the pressure to act upon ... yielding much higher bolt thrust than the 7x57 would.

Hope this helps.


March 4, 2012, 10:01 PM
Definitely use a large ring action, a 93 will likely come unglued pretty quick with that much bolt thrust.

March 4, 2012, 10:26 PM
thanks saands for the info basicly the cartrige is a trimmed down .458 win mag, do you think i would be better off using a savage action and just having a gunsmith cut down the barrel?

Jim Watson
March 4, 2012, 10:27 PM
.458 x 2" American is a wildcat with no factory loads or SAAMI pressure specification. I guess you could put it in a Spanish Mauser if you treated it like a bolt action .45-70 at 19th century ballistics. But if you tried to soup it up to match what can be done in a modern rifle, the '93 would not hold up.

300 yard capability would, like all the old slow calibers, depend entirely on knowing what the actual range was and making sight correction for it.

I never thought of Hart as an inexpensive barrel. If you want decent quality at low cost, look at Shaw.

March 4, 2012, 10:56 PM
im not looking to move dirt in the next county i just want a bigbore rifle the more i look at this picture im thinking a remington or savage action.

March 5, 2012, 04:59 AM
The .458x2" American is the basis for the 450 Marlin though I don't know the pressures of either round.The major difference between the two is the width of the belt.

March 5, 2012, 04:07 PM
The 458x2 is the universal magnum, the round can be chambered in any Winchester Magnum or H&H magnum. Only by pulling the trigger will you notice the difference between the 300 and the 458 barrel...
I wish we could get Mythbusters to give it a shot (I presume it will be a single shot).