What would you guys say the max CUP you would put a brazilian mauser action up to. I have a one I am considering rebarreling to a 220 swift, but all the manuals I can find show the 220 swift up to almost 54,000 CUP. Would this be approaching or surpassing what a brazilian 98 could handle?
Thanks!

Has the action been re-hardened?

Ther is no hard fast rule for this. All actions are different.

My own rule for using a rounds in an old milsurp action that hasn't been re-heat treated is never exceed the pressure in the action that exceeds what the action was designed for in the first place. Of coarse there are exceptions and I break my own rules from time to time.

About 46000 (CUP) / 55000 (PSI) would be my cutoff point. I'm sure others would take it much further, but to my way of thinking the action was never designed for magnum pressures so why push it now that it's a 100 years old.

Assuming you have a 26" barrel, that'll push a 50gr bullet at around 3800-3900FPS. Nothing to sneeze at.

Terry

BTW, P.O. Ackley was a dangerous reloader

Dear Tlp335:

I had a Pac-nor barreled 6.5-06, using maximum loads from the Nosler Reloading Guide, fifth edition with no apparent lug set back or other difficulties on a 1908 Brazilian Mauser of DWM Berlin manufacture. I did lap it in for almost full lug engagment though. Presently, I am rebarreling this same action with a Lilja barrel soon to be chambered in 7x57 Ackley Improved.

As to your question on maximum pressures allowable, I don't know what the 1908 Brazilian will safely take, but I would recommend a spiral bound book called, Mauser M98 & M96 How to Build Your Favorite Custom Rifle by R. A. Walsh, Wolfe Publishing Company, 1998. The author is a self proclaimed Mauser nut, and a design engineer to boot. This book is obtainable from Brownells.

Mr. Walsh stated in his book that the 1908 Brazilian was one of the best actions to use for a custom Mauser if of DWM make in Berlin. Furthermore, he recommends not to re-heat treat the bolt or receiver as mentioned on page 22.

On page 48, he has a figure (table) for recommended cartridges for the M98 actions, which include the 6mm Remington at 63,000 psi, 270 Winchester at 62,000 psi, 300 Win. Mag. at 61,200 psi and 220 Swift, but only at 50,500 CUP.

Lastly, on page 77, he details evidence from other Mauser military rifle publications (but does not name those other publications) that the Mauser rifles were proofed at 80,000 psi or higher.

Nevertheless, the decision is up to you as to what you feel comfortable with. If you want some more information, please private message me.

Sincerely,

Chris Bemis

sometimes you get lucky. That does not mean that your luck will continue to hold and you will not suffer lug setback. It also does not mean that the next time you try it, you will have good results.

The 1908 actions are very good if they have had some degree of maintenance over the years and the rust was kept at bay. They do have a reputation fo rbeing soft and there is no way I would build a rifle on one without reheattreating it. I have an exceptionally clean 1908 myself and will not build on it until it has been recased.

It is poor practice to fully lap lugs in on any Mauser and not recase the action. This is doubly so on a 1908.

No Mauser makes an ideal base for a long range varmit rig for a variety of reasons. If you do decide to chamber this one in .220 Swift, then I heartily reccomend reheat treating the action and not loading the Swift to its full potential.

I'm building a 22-250 on a 1909 Peruvian made in Oberndorf and never gave strength much thought since the action was in prime condition. A.F. Stoeger claimed, in a prewar catalog, that the peacetime commercial & military actions would withstand 100k psi. This is the same level as the "class A barrel steel" specified for the NS version of the '03 Springfield.

Bud W

there is a world of difference between being able to withstand a certain excess pressure without killing the trigger man vs. surviving overperssure loads and being able to give the owner anywhere near the use that would be considered "normal life" for a rifle action.

But then I never based my opinions on advertising copy that is 70 years old.