.458x284 I have been looking and thinking about this.
It would be just about straight with a rebated rim.
Would you think it would work from controll feed action ? 98 action
Any body now of someone that has one ??

What do you think .

Johnch

What part of the case did you plan on headspacing with? If you don't have a shoulder or a rim then usually you headspace on the mouth as in a 45ACP.

Old Elk Hunter is spot on. if you necked out a 284 case to 458 you will have a bulged case. 284 case at the shoulder is .475. Allow .013 case thickness both sides and then seat a .458 pill and you will see that the numbers do not add up. Cartridges of the World discuss under the Wildcat section a 416 being the largest diameter on the 284 case. Still an impressive round, 300 gn Barnes at 2475 fps.
Malcolm56

about the closest you could come to this is the 458xwsm, which is slightly larger than the 284... it would be enough to headspace from..

very muck like the HE mags...

the 458 jamison (404 cut to 2.2, and formed) has 90 gr of h20, which would be slightly less than wsm variant.


with it being a buldged case, you could NOT do the 470 capstick trick.... which is also a buldged case, of headspacing off the rim

jeffe

Thanks for the feed back.
You confirmed my thoughts and feers.
I had just thought it mite head space off the extractor.
I am just looking for another 98 action easy redo.

The WSM case is a good idea ,need bolt face work and feed rail work .
Have to do some looking .

Thanks Johnch

quote:

The WSM case is a good idea ,need bolt face work and feed rail work .
Have to do some looking .

____________________

Johnch,
Surely you've seen this but in case not, go to
www.shortmags.org

click on Wildcats and there's lot's on the .458/.300 wsm round as done by John Noveske. Also, do a search here for the same. he has pics posted, etc.

Since then, John has done the .300wsm in .375 and .416. Looks as though he may be getting a following on these rounds.
Good luck and keep us posted on what you do.

Actually, the .451 (not .458) - 284x1.77 is called the .45 Professional. Designed by LeMag, chambered in AR-15s. Requires custom bolt made of proprietary metallurgy. Straight case cut just shy of the shoulder of the original case, cannot recall whether inside reamed. Keep in mind that the .475 Wildey Mag is the 284 cut to 1.29 and inside reamed to accept the .475 bullet so it can be done ....

It would require headspace on the case mouth which is not always considered ideal. We developed our .458 SOCOM to get around some of the items we didn't feel were ideal on the .45 Pro ....

We use lengthened .50AE brass, rim rebated to the same as the .284 (or .308), necked to have sufficient shoulder to head space. Runs a lot pressure but puts out respectable numbers (300 gr JHP at 2000 fps from a 16" carbine AR-15)

Dungbeetle thanks for the link.
I had not found that site yeat.

I did find a local Smith to do some of the work I need done that I can't.

Johnch