Over on shortmagnums.com there is a discussion on the WSM case necked up to .458 that I find interesting. Diameter of the case at the shoulder is unchanged at 0.538" and the diameter of the neck with a bullet in it is 0.480".

My questions are (1) the difference between the size of the neck (loaded) and the diameter of the case at the junction with the shoulder is only 0.058"...is this enough for proper headspacing, and (2)the difference between the diameter of the neck (loaded) and the bullet is only 0.022" leaving a neck-thickness of 0.011" and is this enough to grip a bullet considering the recoil this rifle would have?

The proponent, a gunsmith, also mentions he has a short barrel with a muzzle diameter of only 0.640" that he will be using to build the 1st rifle...that leaves a barrel thickness of only 0.091" at the muzzle. He doesn't say what the other dimensions of the barrel are but this seems like it is way to thin a barrel...or am I overly cautious?

No word on performance but per the 'smith the case blown out to .458 will hold 95gr of water to the top and 73 gr of water at the neck...if this is the case what kind of performance do you think could be expected using a 400gr bullet?

What do you think of the concept?

Bill,

I have the reamer in 458 WSM. I also have reamers in 375,411,416,458,475, and 500 Rem. short mags and WSM"S. I'm having dies made in all these calibers.

Can you send me the link to the discussion on the shortmagnums.com.

Dan

Here you go...it also has his web-site with a photo of the case,

http://www.shortmags.org/shortmags/forum/showthread.asp?topic=19&thread=628&page=1

Jamison already did it with a .530" shoulder, so I'm sure you could do it with a .5380" shoulder.
Make it 40 degrees if you're nervous.
And according to my calculations, you have a good shot at 2200 fps with a 500 gr bullet in 24" of barrel.

Sorry, edit to add, that was with a 3.1" COL. 2.8" will obviously be less!

[ 08-23-2003, 21:19: Message edited by: Bwana-be ]

since case capacity is same as 458 win. mag., you would guess similar performance but in a 0.3" shorter package and still struggling with compressed loads.

Headspaceing looks comparable to the steep angle of the 505 gibbs with I think a little more meat,
shouldn't this be okay.

Quickload estimates for 350g Hynd RN seated to 0.400" for OAL of 2.62", 20" barrel, around 2450fps and 56,000psi for load density around 120%
with RL-7 the shining star.

rgds

-steve-

ps. miscalulated shoulder angle, more like 36deg. not 44deg. of the gibbs

[ 08-24-2003, 02:58: Message edited by: steve505 ]

If they keep experimenting and working very diligently on this project, they'll have finally succeeded in creating a big .45 caliber "dangerous game" cartridge with less performance potential than the .458 Win. Mag. -circa 1956 - and with more accompanying feeding problems to boot.

But man, they'll at least have gotten rid of that horrible belt, and at least they'll have reduce the bolt throw by maybe a half-inch! Those advantages will surely keep some pilgrim from getting stomped or et......

Isn't progress a wonderful thing?

AD

Allen , LOL, too true!!!

Allen if you want, but I can't wait for someone to put one of these together.
Not sure where all these feeding problems will come from. If you can get a 7mm bullet to feed out of one of these, it should be cake to get a .458" cullet to run like falling.

There's lots of folks chambered the old 45/70 in Mausers, so maybe we should start by laughing at them. I can think of quite a few chambers I'd rather have in .458 caliber, especially when you get into wildcat arena, than a 45 WSM - and the WinMag don't make the list.

Besides, I don't see any reason in the world to have a high-performance big-bore in a short action, unless that's just what you got.
Even the Mausers have more like 3.3" and you can get a lot for that.

Bill,

Thanks for the address to Shortmags Website.

I'm sending for the 458x300 Noveske case.

Want to check it out. Should be close to the 450 AK in volume. Might be a little higher in pressure than I was looking for, will have to wait and see.

Roger QSL

If they want a short-action DG, they should look at the .375-284 or .416-284 McPherson. COL of 2.825" but the one shown in "Cartridges of the World" is loaded alittle hot maybe. And it works in a lever-gun.

Well, for a lever gun I don't think you can beat the Alaskans. There's a 416, 458, and 50 cal.
All serious bruisers. Basically the WSM with a belt.

http://www.sluttstykke.com/download/450%20Tomjac%20DWG.jpg

Here is my version on the 450WSM. I use RUM cases as basis, cut them to 2.1" and ony make a small shoulder (with a modified 460WBM dies). I need also to use a throat reamer. Clymer tools did make the reamer, and a only use a shorten 460WBY dies for case forming, neck-sizing og seating.

Tomjac....wouldn't it just be easier to use the WSM case and neck it up to 50-cal and then reform the neck back where you want it?

Either way it looks like an interesting round. HAve you built a rifle yet and if so how is the performance...looks like a real short-range thumper.

I believe the wall thickness in the neck would be to thin if I did it from a 300WSM case. By doing it from the RUM case, the wall thickness is about 0.35-0.4mm (.014-.016"), and I will have it to be 0.25mm (.01").

I haven't buit the rifle yet, I am still waiting for my short MRC action to arrive.

In fact this cartridge is only 5% smaller in volume that the 458WinMag, so it would be a potential round no doubt about that.