I,ve seen mention several times of changing the bolt of a 425 WR to use 404 Jeffery cases. I'd like to give this a try with my 425. Has anyone done this and what type of bolt do I need to be looking for? Opening the bolt face will not be a problem and I handload so headspace can be managed. I'm not a Mauser guy so please keep it simple!
Thanks.

https://forums.accuratereloading.com/eve/forums/a/tpc/f/...=352101176#352101176
https://forums.accuratereloading.com/eve/forums/a/tpc/f/...=522101176#522101176

aaah yes...the 425 crusher...unrebated and micro-rebated (pic shown)


using rum brass is the most practical and just open to .532 or get a .532 bolt

Boomstick,

How do you use RUM cases in a 425 W-R? The case head is about 0.006" smaller on the W-R, do you propose turning the RUM cases head down?

they are virtualy identical. you can get rum brass ranging from .548 to .545

Thanks for the input fellas. I guess my question was poorly worded. I have no intention of modifying my original bolt, I'm looking for a replacement bolt I can modify by opening the face to accept the larger rim. What am I looking for? A standard 98 bolt from a WW2 Mauser or something else?
Thanks.

I hope you not messing with a nice English gun of any value at all, that is criminal intent and you will be gilflirted at the mention of such a crime...

Ray,
Thanks for your concern. No way am I going to mess up a nice rifle, I just want to be able to remove my stock bolt and and put it in the safe, slide another in and use brass without the rebated rim. Jack Lott mentioned this in his Gun Digest article on the 425 published in the mid 80s. I will not do any conversion resulting in the rifle not being able to be returned to it's original configuration by replaceing the original bolt. Not being a student of the Mauser I need to know if there is a specific model or year bolt I need to be looking for at gun shows or from parts dealers. BTW my rifle is very similar to the one photographed in that article.
Again Thanks.

50,

I'm not sure I understand your question. The 425 WR and the 404 J are not interchangeable. Couple of comments:

1. The 425 WR will work in a standard (.30-06) length action.

2. The 404 J requires a magnum (.375 H&H) length action

3. The 425 WR is a .435" caliber

4. The 404 J is a .423" caliber

5. The chambers for the 425 and the 404 are different. They are not interchangeable.

50 Calshtr,
Yes, you are a shooter and not a shitter, it would be great.
The base diameter of the .425 WR is only .001" smaller than the .404 Jeffery base/head.

You could size down the .404 Jeffery brass .001", neck it up, trim it, and fire form it in the WR chamber.

Any standard Mauser M98 bolt of good quality would have to be a precision gunsmith fit for lug bearing in your action, with bolt face to fit the .404 Jeffery rim.

Headspace is set with barrel aganst the C-ring, and locking lugs of bolt in the action recesses, and a max cartridge as an almost-stopper in the chamber. No-go gage is a no-go stopper.
It might take a trial of several different bolts to make sure the tolerances are O.K. and the lugs can be lapped in to full bearing on each, and minimum headspace.

Go for it.

50 Calshtr - You're trying to get two bolts (of different bolt face diameters) to headspace on the same chamber without modifying anything other than the new bolt. I'm with ya.

Send the rifle to someone that understands what you're trying to do (and has a lot mauser bolts on hand.) If you're not careful with your gunsmith choice, you could end up with the new bolt head spacing correctly and the old one not.

If you have a '98 mauser, then (in theory) any '98 mauser bolt will work, which to say they are all the same length. BUT they will not all headspace correctly on your existing chamber.

It would be ideal if your gunsmith had several on hand to try. That will save you from buying bolts that won't work - or rather bolts that would give you too much headspace on the existing chamber.

new bolt...new shell holder for reloading. just trim, form and load with the new bolt. the original a.r. cart

It seems a new set of headspace gages, both go and no-go (for the .425 WR with a .404 Jeffery rim), might be helpful.

Dave Kiff gauges, or Dave Manson gages, come to mind.

I understand your post now It took a while but better late than never so they say

You want a non-rebated rim .425 WR "Improved" and plan to use .404 Jeffery brass to make the improved 425 WR. OK.

Similar effort as the Harald Wolf/Tony Sanchez .500 Jeffery Improved to eliminate the rebated rim.

A nice 404 can be built on a std. action very easily if you do the magazine and rail work..

My problem is as I recall the .425 has a clip affair on the magazine to handle the rebated rim and I don't know if that would work on a longer case like a .404..

You can do about anything if you have the time and money, but I bet it would be cheaper and better to just build a .404, a Mod. 98 mauser, a Wisner .404 box, and a Lothar Walthar barrel, then all you need is a piece of wood..and about a PU truck load of money, that should get you started.

Do you have to open up the action for the 404?

Yes you would have to open it up in back and about smidgeon in front and rail work would be necessary and then it probably would not work for the .425...Usually these projects become a nightmare, at least most of mine do!

If it ain't broke, don't fix it is my motto and hard earned...

The balistic difference between the two is less than nothing, so whats the point, other than you dropping a bundle for nothing..

Sell the 425 and buy or build a .404 would be cheaper I suspect. The 425 is a fine bigbore btw.

I agree

Buliwyf et all,
That's correct, a 425 case using a rimless case, 404 or RUM, as the base case, formed to 425 WR dimensions, to bypass the problems associated with the rebated case in the original. I guess I'm guilty of not describing my maddness as well as I should. If I can find a good bolt it should feed more reliably without modification to the rails or spring clips. That said I haven't had any problems with the original configuration however I've never used it in a situation more stressful than a bad day at the range. Bottom line, I probably have too much time on my hands and not enough money for another rifle to fiddle with.
Thanks for the help guys.