Building a 404 J

[Ontario Hunter]

5

HH

Am I missing something? A 404J rifle that holds five in the magazine? Wow. That gun must be a handful. Literally.

 

[tward1604]

Reto Buehler hands down if you are looking for as good as they come.

 

[bowjijohn]

What ever you pay …

Whom ever you choose to build your rifle ….

Make sure they understand M98 actions; Paul Mauser’s design parameters and the 404 J

As I’ve mentioned numerous times on here in past 404 topics, if you don’t choose your builder well you end up with a piece of s.h.I.t that cost a fortune and just gets thrown away

 

[Heeler75]

I have been kicking around the idea myself. When I decide I will have Wayne at AHR do mine.

I thought Wayne retired and Matrix took over the CZ 550 upgrades?

 

[Wishfulthinker580]

I thought Wayne retired and Matrix took over the CZ 550 upgrades?

He’s still building rifles just not doing the upgrades. Apparently between the two he was swamped

 

[Ontario Hunter]

What ever you pay …

Whom ever you choose to build your rifle ….

Make sure they understand M98 actions; Paul Mauser’s design parameters and the 404 J

As I’ve mentioned numerous times on here in past 404 topics, if you don’t choose your builder well you end up with a piece of s.h.I.t that cost a fortune and just gets thrown away

Interesting you would mention Paul Mauser's design parameters. I presume you are talking about his formula for calculating the width of magazine box to stagger stack cartridges. Mauser's formula for magazine width was: cartridge width + (cartridge width x cosine 30 degrees). Jeffery initially obtained the proper Mauser magazine width by simply cutting away the sides and front of standard Mauser 98 magazine box and opening up the stock well for magazine. I calculated the necessary width and bought 416 Rem Mag bottom metal thinking I would need to remove a bit of metal from sides of the box, particularly at shoulder, to properly stagger stack 404 Jeffery. Turns out it wasn't necessary. Without modification of the 416 box, the standard 98's receiver feeding rails were sufficient to keep the fatter 404 rounds stacked until the bolt picked them up during cycling. I even tried shaking the stacked rounds loose by banging the butt on the floor with bolt open. Shells stayed in the magazine. If anything, I suspect my action is smoother cycling and maybe (key word "maybe") even more reliable than if I'd followed Mauser specs. My stacked cartridges are held slightly closer to the center of the bolt when it picks them up. There's less angle when they make the jump sideways into the extractor. Also means there's less angle at the bullet end as it enters the very short feeding ramp up to the chamber.

 

[bowjijohn]

I wish you had built mine

Seriously though- there are probably a range of parameters within which the 404 will cycle

Mine did not

I couldn’t trust it

Not ideal for a DG rifle come stopping rifle

Interesting though that you have discovered that Paul’s ratio doesn’t have to be followed blindly

 

[Rare Breed]

I have an AHR 404 Jeff in grade 3 on a cz action absolute killing machine I might be willing to let go.
I fell victim to a bout of day drinking at SCI and Chris Sells caught me in his web…

HH

As if you need an excuse!!! LMAO!!!

 

[IvW]

There was a ZKK602 458WM in the classifieds......perfect donar rifle......with popup peep sight in the receiver best of them all......

 

[pjaln]

Matt Roberts at MNR custom Vermont has his own 404 for sale , it has the lines of a 350 rigby , early FRED WELLS action which is rare and scoped 18,500usd a lot oof gun for the money , ive held it its as good as it looks

 

[Andrew Short]

I thought Wayne retired and Matrix took over the CZ 550 upgrades?

Wayne is building my 404 now. We started with the action and built off of it. Will be ready in November. He no longer does upgrades, only custom work.

 

[Ontario Hunter]

I wish you had built mine

Seriously though- there are probably a range of parameters within which the 404 will cycle

Mine did not

I couldn’t trust it

Not ideal for a DG rifle come stopping rifle

Interesting though that you have discovered that Paul’s ratio doesn’t have to be followed blindly

Thanks, but I'd rather stick with my current day job = not working.

I should add, the 416 magazine was considerably narrower at the shoulder than what Mauser's formula dictated for 404J. I was really taking a chance there. Removing enough metal to meet the formula would have made the box quite thin at the shoulder zone, especially at the top (box was machined with a drift making metal at the bottom thicker). But because the 404 rounds at the shoulder were squeezed a bit in the unaltered 416 box, the rounds were pitched ever so slightly towards the center line of action. This helps point the bullet end more towards the center of chamber even before cycling starts and bolt is closed. Most of the feeding issues with this conversion are encountered because 1) the bullets run into the feeding ramp because 2) the ramp angle is too blunt or 3) the cartridge is released by feeding rail too late. Another problem that I'm reading about a lot is 4) last round in the gun jams and won't feed. That's not a feeding rail issue if the rest of the rounds in the box feed okay. The problem lays with the follower. Carve away some of the follower's upright feeding rail so that final round can jump the receiver feeding rail into extractor at the same time/place as rounds stacked above it. The follower rail is too thick and it's holding that final shell under the feeding rail too long. An easy fix actually.

 

[Ray B]

the Mauser formula for magazine width determines the maximum width of the magazine. The result is the top cartridge touches or nearly touches the cartridge directly beneath it as well as firm contact with the cartridge below it to the side. A wider magazine will allow the cartridge to slide around between the cartridges and the side of the well. A narrower box will hold the cartridge firmly between the side cartridge and the side but will result in a deeper amount of space taken by the cartridges so the magazine will have less capacity.

 

[krish]

Am I missing something? A 404J rifle that holds five in the magazine? Wow. That gun must be a handful. Literally.

I just bought a custom 404j on Cz action. It holds 5 in the magazine. Can close the bolt freely. No round in the chamber. No monkeying loading the chamber and then loading from the bottom. Mine cycles flawlessly.
Thank you @Hunting Hitman
Krish

 

[Ontario Hunter]

the Mauser formula for magazine width determines the maximum width of the magazine. The result is the top cartridge touches or nearly touches the cartridge directly beneath it as well as firm contact with the cartridge below it to the side. A wider magazine will allow the cartridge to slide around between the cartridges and the side of the well. A narrower box will hold the cartridge firmly between the side cartridge and the side but will result in a deeper amount of space taken by the cartridges so the magazine will have less capacity.

In a Mauser 98 conversion, a wider box necessitates narrower feeding rails. Otherwise, the cartridges jump to the extractor/bolt face too late and the bullet runs into the end of the box during loading. Narrowing the feeding rails to accommodate a wider box is a delicate art. I was much relieved to discover the narrower-than-Mauser-formula 416 Rem bottom metal fed shells off the left rail with no modification. And I didn't have to do much to the right rail to make it work. This makes sense because the rails were designed to feed narrower 8mm shells. So they would better accommodate fatter cartridges in a narrow box than a wider box. The thing to keep in mind is there can be significant differences between different manufactured models of 98 Mauser. Mine was BRNO vz.24, one of the best choices for upgrading. Other variants may not take to 416 Rem bottom metal in the same way.

Unless an extended magazine is used, the 404 Jeffery upgrade in Mauser 98 is limited to three in the magazine. Even with the narrower 416 Rem bottom metal, there's still plenty of space below the bottom round in a full magazine. In another thread there was some discussion about starting the fourth round by tucking it below the extractor in an open chamber with full magazine. I'm not sure there's enough room in the narrower 416 magazine to do this (I'll check when the gun comes back from bluing). I doubt it. Immaterial for me anyway because I reshaped the extractor on mine so it will snap over on a fourth round dropped in the chamber.

 

[Ontario Hunter]

I just bought a custom 404j on Cz action. It holds 5 in the magazine. Can close the bolt freely. No round in the chamber. No monkeying loading the chamber and then loading from the bottom. Mine cycles flawlessly.
Thank you @Hunting Hitman
Krish

What does that gun weigh? It must be a brute.

 

[krish]

What does that gun weigh? It must be a brute.

Not really. It weighs no more than regular cz 550 safari magnum with recoil reducer.
Do you have a 404j that does not take enough cartridges. Is that why you think that it is out of norm.
Krish

 

[Ontario Hunter]

Not really. It weighs no more than regular cz 550 safari magnum with recoil reducer.
Do you have a 404j that does not take enough cartridges. Is that why you think that it is out of norm.
Krish

How much is "not really?" My Mauser 98 conversion is PLENTY heavy and it is standard length action, only three in the magazine, and no recoil reducer. Perhaps its barrel taper is a bit on the thick side, I don't know. It's what Lija recommended. I would weigh it for comparison but it's away being blued.

 

[Grumpy gumpy]

How much is "not really?" My Mauser 98 conversion is PLENTY heavy and it is standard length action, only three in the magazine, and no recoil reducer. Perhaps its barrel taper is a bit on the thick side, I don't know. It's what Lija recommended. I would weigh it for comparison but it's away being blued.

Just put my 404 on the scales, 4.73kg(10.4 lb) empty with a 4x weaver steel tube scope. I started with a Peruvian standard m98 action which I did a considerable amount of work on before I even touched the feed rails, moving the bolt stop, milling out the back of the receiver and then the front etc. The bottom metal I milled the back off the mag well and then added a piece of metal to the rear approximately 3.5 mm back, then did the same to the front, I thinned the side walls at the back to gain another couple of mm in side width, i extended the hinge knuckle and the front of the floor plate metal and redrilled the pivot pin hole 4 mm further forward so the hinge would work. When all that was done I then started on the feed rails, widening the opening and slowly tweaking the shape till it allowed the cases to feed whilst also working the front receiver ramp. I would hate to think how much a smith would have charged
gumpy

 

[Ray B]

the magazine width for any box type magazine follows the same needs as shown by the attached drawing. Each diagram shows the heads of three cartridges in a box magazine. Left shows width that allows proper functioning as well as maximum capacity. Center shows too wide a magazine so the cartridges have room to move around- not good. Right shows less than maximum width- the cartridges are held in place but are restricted from compressing into more capacity.