I have a bit of a desire to build a small .500 cal rifle on a M98 action. I am not looking for huge speeds, around 2200-2300fps or a bit more with 450's.

So far there are a few rounds I have been looking at they are the .510 Whisper, 500 Whisper, 500 AccRel and the 510 WSM. Who here has one of these, that run them supersonic? Are they easy to make feed?

of course i am in favor of the 500 Accrel - though there is also the 500 MdM

So do I, except there isnt a reamer hete. Those barrels we spoke of were pre chambered.

Steve

Bruce Bertram in Australia played with a short cased .500 a year or two back. He might be a good source of information

Can't the 500 Jeffery be built on an M98 action?

I would chop off a 300 RUM and use that; headspace on the mouth. Like a fat 450 Bushmaster. Reamer? Use a RUM reamer with a sharp mouth. Throat separately.

Michael458's 500 MDM is what I would do. It's built on a 300 RUM case. He has components, dies, and tons of load info. I can put you in touch with him if you'd like.

Mods and feeding would be the issue I would be most concerned about $ wise. I would think a single stack detachable magazine to help feed the 1/2” beast would be my worry.
https://pacifictoolandgauge.co...ne-bottom-metal.html
Think of a set up like the 425WR for the games keepers for culling.

I made the .50 B&M Alaskan with a rebated rim. [.532]

Head spaces off the mouth.

Starline brass 50AK.

Can also use RUM and WSM brass.

Check out B&M Rifles and cartridges.

Have to check the specks but how about using the 458 case 338 case or 458 LOtt case?? If not that then use the 375 Ruger case..??????

Only the Ruger case is fat enough; no belted mag will work; wildcat 50 cal cartridges are best made from RUMs. Those are easy to make.

I used WSM brass for my 510WSM because it's slightly bigger than the RUM brass I measured. I wasn't looking for big speed though, so shorter was fine. I did get the reamer made long enough to use 300RUM cut at the shoulder.

If you go with .500 instead of .510, then that helps a bit getting things to fit. For example, .500 bullet with a WSM case would let you put more taper on the chamber. I wanted to use 50 BMG bullets though, which are .510".

Good luck with your project and let us know how it goes!

Can't see any reason to just not use the 500 Jeff. Factory ammmo is available and the cartridge was designed to fit the standard 98.

I've built a number of them and used my own on a Tanzanian buff hunt.

Reliable feeding and function is not a slam dunk, but not near the problem I hear about

50 Mayhem a Swedish cartridge made to meet the energy requirements for big game subsonic. Its based on 50Alaskan/12,7*42r (m1867) but made for repeating rifles.
https://en.everybodywiki.com/50_Mayhem

https://vildsvin.se/vapen/nya-...8-mayhem-ar-edition/

.500 Cyrus
https://www.handloadermagazine.com/wildcat-cartridges

I had a 425 WR that had been openned up to a 458 win mag case??? that fed exceptionally well. Had I kept it and wish I had it back..the new owner said it was destined to be a 500 Jefferys!! damn it, had that dawned on me I would still have it if the feed clips would work in that caliber and make of rifle...