I was just wondering what is the most powerful round or the most respected big bore round that will fit in a standard length FN mauser with the factory magazine box?

With the standard magazene box caveat, that is a toughie. Lets just assume you are considering a standard length round, so the most powerful, with some work on the rails and magazene would be the 500 Jeffrey. Not quite as powerful, and a bit more practicle would be a 450 G&A, which is a 2.5" long 404 case necked up, and is a balistic match of the 458 lott. If you favor 416's, there is the 416 howell, a 2.5" 404 based 416, on par with the 416 rem mag.

458 winchester magnum, assuming that you do not want to open up the acion and buy a new mag box.

[This message has been edited by 500grains (edited 10-11-2001).]

I'll go with Paul, the 500 Jefferys...then the 404 Jefferys..458 Win will work but its not a round I really care for...

If you don't want to open the action up and have to buy new bottom metal, then go with the 338 case necked up to 416 or 423...

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

In descending order:

585 Nyati
500 Jeffery
460 G&A
416 Howell
425 Westley Richards
404 Jeffery

The last three are pretty much the same ballistically. The 585 and 500 will require considerable magazine and bolt work.

Todd E

Todd,

You got me with the 585 Nyati. But, the 460 G&A is the full length 404, and needs a mag length action, the 450 G&A uses the shortened 404 case.

Also, considering the belt diameter of the H&H case, I'd consider either the 458 win mag or the 450 G&A to require rail and magazene work, and while you're at it, you might as well use a case big enough to justify the 45 bore. I think 416 is biggest practicle caliber in the 2.5" belted cases.

Paul H,

You caught me. I was thinking of the 460 A-Square, which is based on a 2.5" case. Another possibility would be the 458 Lott or the 470 Capstick. These two will stretch it to the limit lengthwise. I think that the 495 A-Square might work as well, but I am not sure without looking it up.

Todd E

Aaron,
I think that some of these choices would limit you to one or two rounds in the magazine without a complete rework.

The 458 Winchester would be the simplest, but it has it's detractors... but not me with my hand loads.

The best alternative would be the 450 Vincent Short, in Saeed's reloading pages, created by Saeed and Roy Vincent. It is a shortened 404 case necked up to 458, with the idea of use in rechambering of standard 458 Winchester rifles.

To get three rounds in the magazine with this cartridge would not be difficult. Only a reworked follower and windowed magazine walls and no other changes to the box. No stock or bottom metal changes otherwise.

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Good huntin', shootin', and spear chuckin',
RAB

Ron,

The 450 vincent short is essentially a 450 G&A, or 458 HRH, depending on how you look at it.

Last time I talked to John, it sounded like he might finish the 458 HRH before the 500 Jeffrey, though then that has me trying to figure out dies.

O.K. Paul.
The best choice is the 458 HRH, 450 G&A, or 450 Vincent Short, all pretty much the same. That has got to be the ultimate short magnum for the Mauser 98 with a minimum of alteration. Just trying to put in a plug for the host's cartridge pet. Saeed said that RCBS could supply the 450 Vincent Short and Long dies. Surely they could make some 458 HRH dies from a sample of your fired brass.

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Good huntin', shootin', and spear chuckin',
RAB

Paul, Todd,
The Standard Mauser works fine with the 404 or 460 G&A, you just have to open it up a little..Remember the 404 is shorter than a 375 case...I simply use a blackburn Obendorf bottom metal, designed for that conversion and open it up in back and about forty thousands in front, I can do that front part with my fingernail

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

Ray,

What does blackburn charge for that bottom metal? The gun is a 8.25lbs .458 - If I kept the barrel contour the same in a .404 it would be a bit more heavy -which is needed. and the 404 would kick less - which is needed. This is what I have been thinking since I started the post..
I have heard that you need a VERY good gunsmith for the .404 to feed correctly. Is this true?
Aaron

Aaron,

I am not Ray, but if your rifle is already a 458 Win Mag you shouldn't need to do much other than rebarrel it. 404 Jeffery's feed very nicely by design and therefore are somewhat idiot proof. This is due to the long gentle slope of the shoulder. You may need to modify the follower a bit but I should think that would be the extent of any "serious" modifications.

Todd E

Aaron,
If you want to alter the box and rebarrel, then the 404 Jeffery would certainly be the well respected round of choice.

But the 450 Vincent Short/458 HRH still fits your initial proposition better.

I would rather have one of these by rechambering an existing 458 Winchester. Bullet versatility and availability, and bigger holes, if you want "whomp" in a short magnum. The full length 404 will require some opening up of the action for sure, as Ray advises, to the rear.

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Good huntin', shootin', and spear chuckin',
RAB

Blackburn charges about $350 for the bottom metal. Add $60 for the magnum length follower and $10 for a magnum spring.

Aaron,
I pay $280. wholesale for Blackburn bottom metal and a little more for a drop box.....

To convert to 404 you need a qualified gunsmith that is familiar with doing that work for sure, as some rail work will be required either adding to or subtracting as required to have PERFECT feeding and extraction, the number 1 priority for DGR's.....but to simplify the procedure use the original specs by Jeffery and tune from there.....

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com