Need some input on Mauser rebuilds

[Mogas]

Sure could use some input here. I just got in two Mauser receivers with stripped bolts from Sarco. One is a 1908 and the other is a 1909 both made in the waffen fabriken something something Germany. If you were starting a build on these receivers would you want a rockwell hardness test? . My thoughts are to put one build in a 35 Whelen and for the other to barrel in 308 but chamber to swiss 7.5X55. Mostly because I got the dies and a ton of brass for that. the other reasons is to keep chamber pressure down. So no magnums . One of the receivers has some pitting above the woodline around the area the barrel is screwed into. I am thinking just filling these pits with Devcon liquid steel. These are not deep pits at all. What would your suggestions be on this?

 

[cooltouch]

I have a few 1909 Argentines that I'm planning to do something with one of these days. I plan on 7mm Mauser for one and possibly 6mm PRC or maybe 6.5 Creedmoor for another. No magnums for me either. My Argentines were produced at the same factory as yours (I think -- I'd have to check, they're in my gun safe at the moment). Similar to you, a couple of my actions show a slight amount of pitting above the wood line in the chamber area. Personally, I'm not worried about these very slight pits. In fact, I'm thinking that I can just polish them out.

I'm not familiar with the advantages -- or not -- of having a Rockwell hardness test done. Hopefully, somebody else will weigh in on this who has a better metallurgical background than I have. It seems that, to me, a receiver must walk the fine line between malleability and harness. One doesn't want a receiver that is too hard, or else it may be brittle, so one would want a receiver that is hard, yet able to handle high pressures without fracturing. Or so it seems to me. Anyway, given that your receivers are surplus, which means that they've already been fired -- probably a lot -- then I'm thinking the only worries would be if they had microfractures (detected with a magnaflux test), or if they had somehow lost their hardness, which I don't think is likely unless they were in a very hot fire such that temper would have been lost.

 

[Armorer 101]

The problem with Mauser is they made rifles for a lot of countries for different cartridges. About the only way to tell exactly what you have is to measure the outside diameter of the front ring and distance between the center of the front and rear action screws.
If the actions are Argentine, made for the 7.65 Argentine, they were reportedly proofed at 70,000 PSI before sale to the public. This is a bit shorter case than an 06 case so you would need to watch the cartridge OAL on a 35W. Suggest you read the data on the 1906 Mauser and the Argentine Mauser before you do anything.

They are a version of the 98 Mauser if Argentine and should be a Large Ring.
I have built Argentine Mausers and they make a very good Mauser conversion.

 

[Mogas]

I have a few 1909 Argentines that I'm planning to do something with one of these days. I plan on 7mm Mauser for one and possibly 6mm PRC or maybe 6.5 Creedmoor for another. No magnums for me either. My Argentines were produced at the same factory as yours (I think -- I'd have to check, they're in my gun safe at the moment). Similar to you, a couple of my actions show a slight amount of pitting above the wood line in the chamber area. Personally, I'm not worried about these very slight pits. In fact, I'm thinking that I can just polish them out.

I'm not familiar with the advantages -- or not -- of having a Rockwell hardness test done. Hopefully, somebody else will weigh in on this who has a better metallurgical background than I have. It seems that, to me, a receiver must walk the fine line between malleability and harness. One doesn't want a receiver that is too hard, or else it may be brittle, so one would want a receiver that is hard, yet able to handle high pressures without fracturing. Or so it seems to me. Anyway, given that your receivers are surplus, which means that they've already been fired -- probably a lot -- then I'm thinking the only worries would be if they had microfractures (detected with a magnaflux test), or if they had somehow lost their hardness, which I don't think is likely unless they were in a very hot fire such that temper would have been lost.

One other concern I have is Because of the age of the receivers (110 years) there may be some issues within the receiver itself. That area would be where the bolt locking lugs fit into the receiver locking slots. Over time this area may become loose or even set back. I am thinking that the bolt hardness is harder than the receiver so the locking lugs on the bolt should be fine. If I find that is the case, I did find NOS of 98 bolts with oversize locking lugs to compensate for worn receivers.

 

[cooltouch]

Well, there you go then. If M98 bolts are available in a variety of oversizes, you just try them out until you find one that fits. Not unlike the go, no-go gauges for headspacing. Which, come to think of it, you'll need after you've found a bolt that fits your barrelled receiver.

 

[stillquietvoice]

There should be a date, year, of manufacture on each reciever. Usually on top of reciever ring
This is my m43 Spanish mauser made in ovedia plant in Spain.

 

[stillquietvoice]

Some years, early were brittle do to heat treatment processes, learning curve, not sure exactly which ones, but similar to early 03 Springfield actions.

 

[Cypress]

Sounds like you have a Brazilain (1908) and an Argentine (1909). I have never heard of any issues with the heat treat on either of these actions and the Argentines at least are usually highly desirable for builds. The Brazilians usually showed up with considerably more pitting. You can get into some feed issues with certain cartridges and need to adjust the feed rails if you aren’t careful on cartridge selection. I would highly recommend getting a copy of Jerry Kuhnhausens Mauser shop manual as it will give you more information than you will ever need. Also the guys over at Mauser Central are always a wealth of knowledge. Enjoy the builds and don’t EVER tally up what you spent on parts!!!

 

[cooltouch]

Good advice, that. These are custom rifles, after all.