early mauser action strength question

Claven2

Claven2

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Quick question:

How big a round can you safely chamber onto an EARLY carbon steel M98 action such as the pre-WW1 Mauser Oberndorf and DWM receivers like the G98, M1908 and M1909?

I know that virtually any non-magnum .30 should be ok (ie, .30-06 or less), as will the original calibers 8mm JS, 7x57 and .30 Mauser.

But how much bigger is safe before you need to use a WW2 or later vintage nickle steel receiver?

Specifically, what about the following calibers? Which will be allright without serious risk of bolt setback ruining and expensive custom sporter?

-.35 Whelen?
-.358 Winchester?
-9.3x62?
-.30 cal WSM and WSSM?
-.35 cal WSM and WSSM?
-.45-70 loaded hot?
-.280/260?

What about the really big guns like .375 H&H and up?
 
PS: I'm looking for opinions from people who actually know for sure by either having success or failure stories with the early receivers and these rounds or similar rounds.
 
I have an article by Crossman c1912 reprinted in Rifle magazine where he says that the Mauser was not strong enough for the .280 Ross ctg. which is the size add pressure of present day Magnum rounds.
 
You might want to consult Kuenhausen's (Sp?) book. He discusses various conversion options in detail. Are you sure that there was different steel used in later actions? General thought is to stay away from late war actions, though. .45-70 is considered OK in the Tokyo made Siamese Mausers, which are early production. Personally I'd be nervous about the WSM/WSSM cartridges because of the increased backthrust from the larger diameter case heads, from a standpoint of setback, rather than outright strength. Feed might be an issue as well. The other rounds probably operate at pressure levels similar to 8x57S.
 
I have seen visible setback ( about .0015") in a 1908 DWM action chambered in 8mm Gibbs and loaded damn hot. I have also seen 1908s barreled in 7mm Mag which have seen a lot of shooting with no apparent problems. The difference , obviously, was the pressure levels to which the respective shooters loaded.
Generally speaking, I am confident of the 1908s ability to handle any /06 based cartridge and I'm OK with conversions to the short belted magnums such as the 7mm, 338WM, 416 Taylor etc. Sensible loading practices go a long way toward ensuring good service from these actions.
I have some considerable experience with the 1908 DWMs and the 1935 Oberndorf actions. Some may recall that there were large numbers of these imported in the late seventies. These were brand new complete rifles which we cheerfully tore apart to use as the basis for custom sporters. I'm sure many collectors feel we should burn for eternity for this!
Anyway, there is a big difference between the two actions as far as hardness and the ability to handle high pressures is concerned. The 1935s are hard and tough and will generally have no trouble digesting most anything. The 1908s are safe enough but will be damaged by continued use of too hot loads. This especially in those chambered for magnums.
I don't consider the WSMs to be a good choice for mausers of any description. Of course I don't really consider them to be a good choice for anything at all!
In summary, I would be inclined to stick to standard cartridges in a 1908 (30/06, 270, 280 or any of the 308 based cartridges as well as the 57mm cartridges). The 1935s are good for any of the above as well as any standard length belted cartridges (264, 7mm, 308 Norma, 300 Win. 338 etc.). Bullet diameter is, of course, of no consequence. Pressure levels are the same. Ultimately, pressure levels are determined by the reloader so he can stress his action unduly or not as he chooses. Always remember, that extra 100 fps really means nothing to Mr. Elk! Regards, Bill.
 
Well, I'll dive in. I've built numerous magnum rifles on 98's, from pre-WW1 vintage to 50's FN production. On the early ones I've tried to stay with the lower pressure rounds, but that's just a recent thing for me (getting cautious in my old age I guess). I did a 7 Rem Mag and a 264 Win Mag on early 20th century actions, and had no problems at all. Still, it is getting close to 100 year old steel. With regard to the 375 length cartridges, I would be more concerned with how much meat I would have to take from the action affecting the safety factor, then I would the pressures involved. When you modify these, try and take as much of the cut from the rear of the action as possible (which will require a modified magazine box), rather then the front lower lug area. There is also the option of having the action reheat-treated when you are done your modifications. There are a couple of outfits stateside doing this, I don't know anyone doing it in Canada at the moment. The Brits built hundreds if not thousands of magnums on these actions (300 H&H, 375 H&H) and even Selby's old 416 Rigby was built on a standard circa WW1 98 action. There have been cases of lug set back on 98's built into 8 Rem Mag and 340 Wby's I've seen, but I've also seen the same thing on 7 and 8 Mauser chambered rifles, so I don't know if it's the metal or the reloader. HTH - dan
 
Hi Bill,

Great post! So I guess it should be OK to forge ahead with my .35 Whelen on an Argentine 1909 project? I'm at the point where I've got everything I need to go ahead, but if this receiver is a bad choice, now is the time to know it before I start dropping money on too weak a receiver.

I'm thinking it should be OK given that the Whelen was purposed designed in the 1920's for use in WW1 Gew98 bring-back actions.
 
Dan,
Something to keep in mind re the British rifles built in the big calibers is that they were all low pressure rounds. The huge 416 Rigby case was loaded to a mere 2400 fps with a 400 gr bullet. Load the same cartridge to the levels embraced by the modern north American shooter and the action might not last so long! When pressure levels are low, action strength is plainly less critical. I've seen a few European 375 which were ruined with now accepted loads.
I think the 1909 will be fine in 35 Whelen. Regards, Bill.
 
I won't repeat all the excellent advice already given except to add that it is all too often forgotten that the old cartridges gave very good performance at very low pressure levels, this type of thinking would go a long way if applied to gun building in contributing to low wear, increased precission and reliability in designing any type of firearm instead of always trying to opperate at the edge. This has unfortunetly been alot of peoples mindset in the last years.
bigbull
 
The criteria that I use is to multiply the pressure of a factory round x the base diameter squared. In other words if you know that the mauser is safe for say a 30-06 then anything which develops the same or lesser product of pressure and base diameter should be safe.
My logic is that the thrust on the bolt/breach face is the product of the pressure and the base area. If you want to be fussier, you could use pi radius squared instead of diameter squared but the answer would be similar.
I also suspect that usually a rifle is limited by breach strength rather than barrel strength in the chamber area.

cheers mooncoon
 
It sounds like a Custom rifle on a Mauser action is a pretty standard Project, yes-no? I'm gonna have to look into building my own rifle at some point. You guys know so much about this stuff it's mind boggling. I hope at some point in my life I know half as much as you guys. :D

Wally
 
Wally, the Mauser sporter project is a project one does to a rifle that you want ot put your mark on and enjoy for many years. Unless your labor is free and you have the parts cheaply, don't expect to build one of these for profit. You WILL lose alot of money on one if you ever sell.

That being said, a properly built Mauser is a thing of beauty and mausers really make beautiful sporting arms.

I think alot of guys hold out for the 1950's FN actions these days as they are made of better steel, heat treated better, and the actions are inherently stronger being not C-cut, but there's ALOT to be said for using one of the fine old actions too. Certainly the rifle will almost ooze history!

I really do favor the old DWM and Oberndorf actions for modern sporting gun projects, but one must accept the action's limitations. What these actions CAN do, they do very well IMHO.
 
Hi Claven...Much good advice above. I have pre-WWII actions in 35 Whelan, 338-06, 270 Win. and 30-06. No problem as all are '06 size cartridge cases and pressures. I have a two barrel takedown I built on an early Huskavarn action-like the FN they used stronger modern steels. I had to cut 1/8" or so away behind the lower lug and the thought of using a low carbon steel receiver (90 000 psi vs 125 000+ psi yeild strength) scared me.

All rifles were proved with 3 overpressure rounds developing about 10% over SAAMI max chamber pressure and held up fine with no increase in headspace. 3 thoughts or cautions on the project.

Lap the lugs in so they bear evenly. The last thing you need is one lug doing most of the work.

Stay away from M98 actions made during the second world war. Slave labor (sometimes deliberatly sabotaging the heat treating) and re-melted scap metal don't make for great actions.

The older gunsmiths I have talked to all speak of seeing M98's, even some FN ones, shearing off the upper locking lugs when chambered for Weatherby or H&H improved cartridges. (This is why Roy W stopped using FN actions and started making his own actions in Germany.) This tells me to stay with cartidges that produce normal (not Weatherby like) pressures and only enlarge modern FN type receivers.

Let's see pictures when your done, good luck and have fun! Sportingrifle.
 
I remember reading an article that the '09 Argie's were the first choice of custom makers and the '08 Brazilian's were the second choice. I believe it was in Rifle magazine.

RePete.
 
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