JP Sauer Rifle

[mike ford]

Tom,
If you live close enough to me (East central Alabama) to bring it to me, we could have it closing on your go gauge in just a few minutes. I know what you mean about Americanized ammo. My brother had a 6.5x55 and bought American ammo for it. When I measured the head diameter of hie cases they were the same as that factory's 30-06, which was already .005" less than the drawings show (.473"vs .468"). This is why I don't feel bad about making cases for .360 base Metric cartridges from 38-55 and 30-30 cases. Also, when Hornady started loading 9.3x74R ammo it would chamber in European rifles, because the rims were too thick (I usually have to thin the rims of 38-55 and 30-30 cases when I use them for donor cases, but not always. When I don't need to thin them, I don't know if the rifle was made with excess headspace or if someone recut the rim recess). Back to your rifle. If you can't find ammo that will chamber, it would be easy enough to deepen the chamber by hand, without removing the barrel. It only needs a couple thousandths and to set it up to use the lathes, I would need to take that much to find my "place" to start measuring anyway.
Mike

[Thomasg]

Mike
I appreciate your offer but unfortunately I am way up here in the frozen North! Your a true gentleman to offer.
Thank you very much,
Tom

[mike ford]

Tom,
Sorry, maybe you can find someone closer to help.
Mike

[Thomasg]

After deeper research this turns out to be what is referred to as an M88G, listed by DWM as case number 560. By one source reported to have been discontinued by most companies in 1975. This helps explain the variation in dimension.

[Axel E]

This is a very early Mauser actioned hunting rifle. Both the Mauser, Oberndorf commercial serial number 3826 of the action and the Sauer & Sohn 97602 of the completed rifle date to 1902. At that time Mauser sold left-over actions and parts from the 1897 military tests to the civilian market. So this rifle was built on a small ring transitional action, still without bolt sleeve lock and “safety firing pin”. Sauer & Sohn was one of the first gunmakers to sporterise
Mauser 98 type actions, at the same time as Rigby did in England. Many features later adopted by Mauser and now deemed “typical Mauser commercial” were originally pioneered by Sauer & Sohn. Lever release floorplates, Schnabel foreends, side panels and ribbed half-octagon barrels were standard on S&S sporters years before they appeared on commercial Oberndorf Masers.
The rifle is certainly set up to use the then M88/8 mm cartridge, renamed 8x57I in 1925 (a year before the American SAAMI was founded). There simply was no other 8 mm smokeless, jacketed bullet rimless cartridge suitable for modern Mauser rifles available here in 1902. But nothing was standardized in 1902. Even the military cases were altered over the years then to accommodate developments like machine guns, powders and brass. Many rifles and shotguns would take cartridges by one ammo maker only unless the gunmaker had reamed an oversize chamber to accommodate as many variation as possible. This confusing situation started to be changed in 1909, when a committee of gun- and ammo makers as well as proofhouses, hunting organizations and so on was founded to “normalize” the standards. At first just 4 most popular cases were normalized at first, the Schuetzenhuelse 8.15x46R, the 9,2x72R, the M88/8mm = 8x57I and the then brand-new Mauser 10.75x68, but more to follow soon. In 1922 the dimensions of 8x57 cartridges were altered slightly again, trying in vain to circumvent the provisions of the Versailles treaty ban. 8x57I (R) dimensions were slightly tweaked further in 1940 to prevent S cartridges chambering. In 1926 only recommendations were issued as to minimum barrel dimensions for each cartridge.
As the American SAAMI was founded in 1926 I don’t know which one of the changing metric dimensions they used as a base for their own standards. Additionally, did they correct Millimeters correctly to inches? The inability of Brits and Americans to read and convert metric to imperial numbers is a habit of long standing, from Taylor and Keith to some 1990s Mars missions. As many SAAMI numbers on European cartridges are far off, like their “8 mm Mauser” pressure, I would not trust any such SAAMI chamber gauge as is, but try at first where it really hangs up at first by smoking it, then deciding if the variation is critical.

[mike ford]

Axel,
Thanks for the detailed explanation. I'm a little bit ashamed I missed the fact that it is based on a transitional action, it is as clear as the nose on my face and I have one of those actions myself, so there is no excuse.
Mike

[Thomasg]

Mike, please do not feel that way. I am grateful for your knowledge and experience. All of you inspire me to learn more, which is why I joined. I invested in a hard copy of W.B. Dixon's "EUROPEAN SPORTING CARTRIDGES" just to learn and study the early differences of these cartridges. Thank you and Axel so very very much for your time and patience with novices like me.
All the best,
Tom