Mystery

Odinson

CGN Ultra frequent flyer
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A neighbour brought over a couple of interesting rounds. One head stamp is 300 Win mag super and the other is 7mm. Neither of the rounds are 300 nor 7mm. The projectile measures .456 / .457 diameter and case length is 2.021 give or take a couple of thousandths. The cases have obviously been "stretched" to accommodate the larger projectile but I have no idea as to what it might be.
 
Sounds like 458 Winchester.
As per Hornady 9th reloading book, a 458 Win Mag case is maximum 2.500" long - "trim to" length is 2.490". So, those brass are much too short for 458 Win Mag, but would probably fit and fire in a rifle chambered for one. I presume the brass is "belted magnum" stuff - a CGN guy posted that he would use 300 Win Mag brass, Unique powder and Cream Of Wheat to blow out for the brass case neck for his 458 Win Mag - that required "trimming to length" - I used 7mm Rem Mag brass to do the same - much less or no trimming required. The "belted case heads" are all the same - based on .300 H&H or .375 H&H size - so "headspace" would rely on distance from closed bolt face to forward edge of the "belt". I am guessing, but a case that short would probably be using parent case wall as the "neck" - that might be thicker brass for neck then normally found - might explain why the bullet might be a thou or two smaller than 458 Win Mag?? It is also possible that the belt was lathed off those wildcat brass, and would then rely on the case mouth for headspace dimension, or possibly the case rim, if it was left after the belt was taken off.
 
As per Hornady 9th reloading book, a 458 Win Mag case is maximum 2.500" long - "trim to" length is 2.490". So, those brass are much too short for 458 Win Mag, but would probably fit and fire in a rifle chambered for one. I presume the brass is "belted magnum" stuff - a CGN guy posted that he would use 300 Win Mag brass, Unique powder and Cream Of Wheat to blow out for the brass case neck for his 458 Win Mag - that required "trimming to length" - I used 7mm Rem Mag brass to do the same - much less or no trimming required. The "belted case heads" are all the same - based on .300 H&H or .375 H&H size - so "headspace" would rely on distance from closed bolt face to forward edge of the "belt". I am guessing, but a case that short would probably be using parent case wall as the "neck" - that might be thicker brass for neck then normally found - might explain why the bullet might be a thou or two smaller than 458 Win Mag?? It is also possible that the belt was lathed off those wildcat brass, and would then rely on the case mouth for headspace dimension, or possibly the case rim, if it was left after the belt was taken off.
Probably a 458 x 2" American. It's a wildcat based on a shortened 458wm case.
 
Thank you to all that replied. I don't know of anyone with a rifle in this calibre, nor would I fire them if I did. Best thing, and I'll recommend to my neighbour is to pull the bullets, dump the powder and make some fishing weights with the brass an bullets.
Thanks again!
 
Odinson: The .458 X 2-inch can be safely fired in a 458 Mag chamber. Think of it like shooting a .38 Special, in a .357 Mag. Still, even if you could, you are wise not to shoot them off. Never know what the load is. Always a problem, when dealing with wildcat cartridges with no accompanying load data.
 
Odinson: The .458 X 2-inch can be safely fired in a 458 Mag chamber. Think of it like shooting a .38 Special, in a .357 Mag. Still, even if you could, you are wise not to shoot them off. Never know what the load is. Always a problem, when dealing with wildcat cartridges with no accompanying load data.
Thank you for the info. I was doing some research for a neighbour. My advice to him is to pull the bullets and dump the powder because like you say, it isn't wise to shoot them off. I'm just guessing but it wouldn't surprise me if these were "compressed" loads because both cannelures are exposed above the end of the case.
 
A neighbour brought over a couple of interesting rounds. One head stamp is 300 Win mag super and the other is 7mm. Neither of the rounds are 300 nor 7mm. The projectile measures .456 / .457 diameter and case length is 2.021 give or take a couple of thousandths. The cases have obviously been "stretched" to accommodate the larger projectile but I have no idea as to what it might be.
458x2" Cool find.
 
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