BTW, the Dumoulin receivers are more designed for mounting scopes as they lack the charger bulge, have flat tops, etc. They resemble the Parker Hale receivers and are made of modern steel with modern techniques. You can find bare receivers from time to time on Gunbroker (Numrich is now selling receivers and other collectible parts on gunbroker auctions as well which is why you are not finding them on the web--not through their website).
The 1938 receivers sold by Sarco are actually m1908 receivers sold primarily to Latin American countries. When these were imported into the U.S., for some reason, all of these mausers including German prewar receivers were called 1938 Mausers when they were actually of various types and years of manufacture. Not sure if it was one importer or just a general thing--my pre-WWII Oberndorf was listed as a 1938 model receiver when it was not.
From Sarco
"ORIGINAL 98 MAUSER, 1908 BRAZILIAN RECEIVER, MADE BY DVM IN GERMANY (STANDARD LENGTH LARGE RING ACTION & RECEIVER)
Original German 98 Mauser. Actions Once again available we havent sold these for years now. These are 1908 model Mauser actions made by Deutsche Waffenund Munitionsfabriken one of the greatest German military factories at the height of Mauser productions - Actions are with all milled parts - May have minor pitting. Less than 100 left!! While they last."
These are going to be pre-WWI actions and would be okay if you plan on rebarreling in its original calibers (7x57 or perhaps 8mm) or calibers with similar pressure levels. One issue that you may or may not consider is that the magazines and feeding rails of these receivers are built around the military issue cartridge--if you stay within the profile of these (cartridges based off of the military cartridge), then cartridge feeding from the magazine is not an issue so much but some of today's cartridges will require working on receiver feeding rails. Some of these cartridges will require opening up the bolt face (or like the 7.62x39--closing it up).
A THR poster, Slamfire, has done a lot of research on the steels used in these old warhorses which you can find somewhere here in the archives. You would need to check with Sarco but some of these could be Brazilian 1908's that were re-heat treated for the .30-06 after WWII which opinions vary on their suitability after this.
The major issue with these are if you plan on firing modern higher pressure cartridges in these old pre WWI receivers is that Mausers of that era were built from carbon steel using case hardening over a relatively soft interior. Firing higher pressure rounds than designed causes the softer steel in the receiver bolt lug recesses to deform--leading to increasing headspace. The other problem is that well worn examples may have worn through the case hardening at the surface of the bolt recesses exposing the softer steel underneath--some have also done this by excessive lapping the bolts and recesses to make the action smoother or to fit a bolt to the receiver. Swapping bolts to fix the headspace issue will not fix the issue for very long and effectively the receiver is kaput.
Early WWII era receivers are better made from a steel standpoint and some of the 1930's receivers from some makers such as CZ-Brno, Oberndorf, Steyr are fine if not abused. FN also made Mausers during this era which have mixed opinions regarding receiver softness--post war sporters etc. are ok. However, late WWII 44-45 German receivers workmanship including heat treatment and steels can be suspect.
