Posted this on the Gunsmithing forum earlier,

Picked up my 404 Jeffery last week. It is built on a 1909 Argentine DWM M98 action and has a Lothar Walther barrel. I was out in the desert this past weekend so I decided to give the 404 a go.

I set everything up and shot 4 rounds (400 grain Woodliegh solids) that chronographed at 2,240 fps and grouped decently at 100 yards. The scope on the rifle is a 1.5-5x Leupold with Heavy Duplex reticle that does not allow super precision aiming at 100 yards.

Anyway, I shot another 4 rounds of 400 grain Woodliegh softs at the same 2,240 fps. The group also showed some promise.

Now for the BAD NEWS! I started to shoot another 4 round group and as I inspected the brass after each shot, I started to notice bulging around the bottom of the case. A couple of the cases actually had a slight line around the area that was bulged. Like a precurser to case head separation.

I definitely think I have a case of LUG SETBACK. There also now seems to be a little bit of extra play in the bolt when it is fully closed. I inserted a bolt from another 1909 Argentine M98 action that I have and that bolt did not seem to have the same "play" in it.

Very frustrating, since I had the bolt and action heat treated after the action work. I was really frustrated with it and didn't want to think about it today. However, I have to start thinking about what to do to get it fixed. I'm sure it will be a long and expensive repair.

I really don't know much about this. Does Lug Setback damage the barrel at all? I hope that the Lothar Walther barrel is still good.

Can the action be salvaged? Can I use another M98 bolt and have it headspaced and heat treated?

Help!


Tim

quote:

I had the bolt and action heat treated after the action work.

That is the problem.
There is no objection against: " leave the action as it is ".
I inspected many actions which were damaged after heat treatment or attempting to harden. They showed cracks or lug set back, sometimes blowed up.
Only a little surface hardening, done by a specialist, is allowed.

First, I'd get a no-go guage and check that your headspace is out of tolerance. If it is, kiss that action goodbye. When you pull the barrel look at the locking lugs and see if they are set-back. It will be obvious.
As I've said a million times before, early Mausers were case hardened snd done at a time when the science of heat-treating was questionable at best. Re-heat treating them is a gamble. God knows, I've tried it myself and I have a vacumn furnace and access to a multi atom atomic absorption instrument so that I have some idea of exactly what alloy I'm dealing with. I have had only marginal results and basically no longer use military Mausers as a basis for a big bore.. The only ones I know will hold up to over 45Kpsi are VZ-24's( how long they will hold up I have no idea as the failure mode usually isn't immediate.. -Rob

What about a 1935 Oberndorf Brazilian Mauser ? Use or not use for a custom project ?

You honestly won't know until you try it. Personally, I would not exceed 45Kpsi on a Military Mauser except maybe a VZ24. To be clear, there are enough inexpensive actions around well suited for a big bore, that using Mausers just doesn't make sense anymore. You can go out and buy a CZ550 action for $500 and never have to worry about it.By the time you finish reworking a military Mauser to DRG stds, you'll have nearly as much in it and still have the worries.-Rob

I've heard of these older Mausers setting back in the larger magnum head sized cases, loaded to magnum levels. I also would not rule out the following.

Was not headspaced properly when chambered
Chamber cut too large
Undersized or poor quality brass
Sizing dies that size the case down too far and set the shoulder back causing headspace
Excessive pressure due to either too large a projectile, tight bore, short throat, too much powder. etc…

I would examine all the possibilities and eliminate them one at a time. You’ll find out that in a lot of instances it is more than once cause added up.

I would start by measuring the cases, new, sized and unsized after firing. I would then check the rifle for headspace, chamber cast it, slug the bore and measure the projectiles used. If all the tolerances are within reasonable limits, then you can start to suspect the action metallurgy. I would also check to see it the bolt is properly matched to the action type and model. A bolt isn’t always a just bolt as there are many variations for the Mauser type M98 military and commercial…

quote:

Originally posted by Frank Beller:
What about a 1935 Oberndorf Brazilian Mauser ? Use or not use for a custom project ?

That is the worst action in the world for a custom project. If you want to get rid of it cheap let me know as I like cheap and tacky mauser actions.

Shumba,

Of course you should check the action for lug setback.

However, keep in mind that .404 jeff was made to a couple of different specs. Perhaps your ammo/brass/dies is for one spec and your reamer is for another. That could lead to case strech and give the appearance of a headspace problem.

I suggest a chamber cast and find out what spec you rifle is actually chambered for. Then check that against your ammo/dies/brass to find if they are the same spec or not. Of course the headspace and action check which Rob suggests should be done as well.

505 Jeff shooters also face a similar problem.


Good luck with it!

.

number 1
with a digital caliber, MEASURE all the cases shot for length, assuming they were the same lengh to start. It almost won't matter, as an increase in headspace will be more than .001-.003

number 2
"bolt play" or rattleon an EMPTY chamber means very little, in this situation unless the setback was so horrible that it's in TENTHS of an inch. a loose bolt means you don't have a tight fit on all your lugs IN THE FRONT OF THEM. The rifle is headspaced from the REAR of the lugs. It means the front edges of the primary and safety lugs have clearance. the end.

another bolt in the same gun means ZERO as the headspace is from fore to aft, not aft and play

number 3
do your dies match your reamer? doesn't actually matter if there are or aren't a couple drawings (Alf, Call Dave davidson, he sent me a drawing pack on the 500 jeffe)

number 4
go resize these brass, and notice of there's any difference in effort, assuming they are all the same load

number 5
assuming proper powder (what are you using?) 2240 is about 40kpsi... less pressure than a 8x57!!! more bolt thrust, due to surface area, but less pressure.

number 6
was the bolt NOTICABLY harder to open?

number 7
"lug" setback is ACTUALLY lug race/way setback... that is, the action is crush and dented (impacted) UNDER the position of the fully closed lugs, NOT that the bolt is damaged


Conclusion
(fellow-traveller opinion - that being able to insert another bolt and it NOT rattle doesn't actually test anything, but further leads me to believe lug setback aint the deal)

You probably don't have a lugset back... the major major major shooter felt symptom is hard bolt lift on moderate loads.

you MIGHT have a headspace issue, sure enough, so stick a headspace gage in it FROM THE SAME PRINT AS THE REAMER.

If you feel it's lugset back, and are unwilling to NECK SIZE ONLY your cases and try again, then have the same smith that built it take the barrel off and check it. If I built it, we would cast the chamber and cast the dies and then measure them to spec.


jeffe

Alf,

Perhaps you and I are using the word 'specification' differently. It seems you are using it in the formal sense, such as the official CIP specification (there being only 1 from CIP for .404). But I am using it to indicate the end-result chamber dimensions, brass dimensions, ammo dimensions or die dimensions, as applicable. Because there are reamers out there of different dimensions, rifles get made to different "specifications". This is what got Ruger hung up about the .404, causing them to eventually drop their efforts with that caliber.

BTW, in the past 3 years or so, 2 AR members in addition to Shumba had trouble with custom .404's. Maybe they all bought pre-chambered barrels from the same source.

.

It's an undeniable fact that guys who build custom .404's often experience headspace/misfiring problems because of differences between chamber dimension and ammo dimension. Why does this problem crop up with .404's but not with other calibers????

???

See my post above for the answer.

I measured Tim's once fired cases & compared them to my cases fired five times. His measure 2.892" mine 2.870" . A wee bit too long . All three cases I measured were the same so I'm betting headspace was never set correctly. Any bets? We'll find out soon, when the smith who built mine takes a measure w/ his gauges. The rifle is beautiful though, hopefully Tim posts a pic.

Firstly, lug setback can happen in any cartridge. It normally happens when there is a headspace problem. This can happen in various ways, such as a barrel not screwed in completely (saw one straight out of the box - Ruger M77), lugs not making full or even contact, incorrect chamber depth from the beginning. Any slack exaccerbates the pounding.

Mausers are suface hardened, and if machined away, it has to be done again and not heat-treated (Norbert has stated this already). Without surface hardening then, it is bound to give way over time, especially with the hotter loads. Case stretch is your guide or early tell-tale sign. War-time Mausers are not all equally hardned due to the haste to put rifles into the hands of soldiers and this in not checked by most gun buiders as they take it for granted that they are OK; so we kick off with a problem.

The missing link in testing at proofhouses, as I said before, is X-ray testing which can be done at a nominal fee. Prior abuse may not always show up on the surface, as cracks kan be obscured.

I guess we should only go to top gunsmiths for specialsed work such as building a big-bore DGR.

Chris

.

Alf,

Baie dankie. Sal groete oordra. Mag 2006 jou beste jaar wees.

Die 45-70 bly darem 'n lekker vark geweer as jy langs die land sit. (Met Rhino koeels vir daardie groot oopmaak van die petals, dan klap jy hom ordentlik)

Kersgroete
Chris

500 Grains,

I can't help but to think that perhaps Ruger has made a decision between the 404 Jeff and the 458 Lott. American companies are not known for offering the full spectrum of big-bores. Only very recently did they venture into this market segment that consists of only a few gun nuts that spend their savings on the extravagance of hunting buffalo and elephant.

Truth be told, both of the above can be done today with a 9,3 or a 375 H&h with premium bullets. Only 20 or so years ago it was still done with RN FMJ bullets. Now we have a multiple choice of premium expanding bullets and mono-metal FN solids and this imho brings the requirement of bore size down.

Chris

quote:

Originally posted by 500grains:
It's an undeniable fact that guys who build custom .404's often experience headspace/misfiring problems because of differences between chamber dimension and ammo dimension. Why does this problem crop up with .404's but not with other calibers????

???

See my post above for the answer.

500gr,
Not in intention to be rude, but the problems with the .404 Jeffery seems to be a local North American problem.

quote:

Originally posted by fredj338:
I measured Tim's once fired cases & compared them to my cases fired five times. His measure 2.892" mine 2.870" . A wee bit too long . All three cases I measured were the same so I'm betting headspace was never set correctly. Any bets? We'll find out soon, when the smith who built mine takes a measure w/ his gauges. The rifle is beautiful though, hopefully Tim posts a pic.

\Ah,\

SP, we have a headspace issue, not (probably) lug setback? .022 longer than yours?

Pull some of his unfire rounds and measure those.


jeffe

quote:

Originally posted by husky:

quote:

Originally posted by 500grains:
It's an undeniable fact that guys who build custom .404's often experience headspace/misfiring problems because of differences between chamber dimension and ammo dimension. Why does this problem crop up with .404's but not with other calibers????

???

See my post above for the answer.

500gr,
Not in intention to be rude, but the problems with the .404 Jeffery seems to be a local North American problem.

That is true. I have only heard of the problem in the U.S. The corresponding problem with the .500 Jeff seems to happen everywhere.

quote:

Originally posted by truvelloshooter:
500 Grains,

I can't help but to think that perhaps Ruger has made a decision between the 404 Jeff and the 458 Lott. ]

Ruger did their .404 work quite a few years ago now, long before the .458 lott offering, and if I recall correctly it was before their 416 rigby offering. The reports coming out of Ruger were that the .404 was nixed due to "ammo problems", which would correlate to what at least 3 AR members have experienced.

Undoubtedly some reamer maker is going from a non-standard drawing.

Take it to a good trusted gunsmith other than the one who built the gun. Pull the barrel and look! Usually its the action locking lugs that will show a definate STEP when the metal is being hammered back. With a depth Micrometer, measure from the action ring all around the locking surface. Anything more than about .002 asuming the ring is square unequevocably demomnstrates a problem IMHO. In the ones I've seen it's obvious. The bolt lugs rarely show anything.
Given it's a .404, the Gunsmith probably got his headspace guages at the same time as he bought the reamer. Try his no-Go guage. If the bolt closes you have your answer.-Rob

Yep,happened to me too except my 1909 was chambered for 257 Weatherby. After 18 rounds it was obvious something was wrong. Back to the smith for headspace with his gauge used with his reamer and sure enough the action lug recesses were hammered back not the bolt locking lugs. Went in with a butterfly cutter and cleaned up recesses, made sure bolt lugs were square and rebarreled to 25-06 and no further problems. After research I found that the 1909 Argentine must be checked for hardness anytime you rebarrel from the original military configuration. Take nothing for granted with a 1909 Argentine.

the barrel should be fine as long as there is no destruction , as for the set back , have to measure to see if it is , as for the rehardening , i read pos book about that jazz with the old 03 springdinks and still think it isnt a good idea to mess with the way paul mauser designed the thing , the finest rifle i ever owned was the worst mauser i ever saw ! but im a bit set on my mausers . if i can help with a bolt or suggestions call me up (717)440 2262 brent est.

this is for the guy with the 1935 mauser , if you dont want it to use for a custom , then i might i trade you for a vz24 action , as i dont have one of those yet ? as for the idea of it being bad , well have it checked , then decide for your self , as i have some old mausers and have changed them to ever thing from 7mm to 375 ( yes in a standard action ) even went so far as to strech one for the 475 a&m

Since we haven't heard back, I am assuming this turned into a sizing issue.

quote:

Originally posted by BuddyK-9:
Yep,happened to me too except my 1909 was chambered for 257 Weatherby. After 18 rounds it was obvious something was wrong.

difference being the 404 was probably 40kpsi and the webby was 65kpsi (assuming factory loads)

which means there's no relationship in the rounds, other than both being in a mauser.