10.75x61 Mauser

[Themauserkid]

Some of you have seen this already, but I wanted to share it here as well, in hopes of finding out more about it. I typically try to buy rifles in original as possible condition, but this one was too interesting to pass up. I originally bought this billed as an 11.2 Sch?ler, thinking I had finally found one. Before I was able to cast the chamber, I started taking some rudimentary measurements and could tell that it was decidedly not the big Sch?ler chambering. After an order of casting material arrived, it became clear this was a old forgotten round, DWM case number 523 or 10.75x61! This was a Haenel development, and already obsolescent by 1914.

I had a lot of help getting actual cartridge dimensions, pictures and copies of the DWM ledger listing this round, from a collector in Germany. He also experimented with some case forming and found that it is basically a 9.3x62 necked to 10.75mm. I would imagine he is probably a member here as well, so perhaps he will chime in on that.

After all that, I still don?t know ?who? built this rifle. It is retailer marked by Eduard Kettner of K?ln. I spent some time researching the makers that typically built guns for him, and came up with some possibilities, but nothing I could definitively nail down. While it?s a Haenel development, it doesn?t look anything like Haenel?s Mauser pattern rifles. It has some definite similarities with Sch?ler built rifles, but also possibly too many inconsistencies. It?s been a while since I dug into this rifle, but I need to go back and take a look under the wood line again, it is pretty sparse from what I recall. The action carries Oberndorf?s internal inspection and serial 24572.

Unfortunately the bolt and floorplate have been replaced at some point, and it?s missing a couple of small parts, forward swivel etc. but it?s still a rather interesting rifle to me.

[Themauserkid]

Additional photos

[Themauserkid]

Here?s a picture of the original round as supplied from Germany, and then a friend on this side of the world, loaded some test cases, shown in comparison to his 10.75x57.

[mike ford]

Themauserkid,
This is a very interesting rifle, as you stated. You didn't ask a question, so I hope you don't mind if I offer a couple unsolicited opinions. The case number was assigned to a 10.5 cartridge, and another name for the 10.75x61 was 10.5x61 according to Dixon. The bore( not groove or bullet) diameter marked on the rifle is 10.2 mm which is .402", but could be as large as .405". This would result in a groove diameter of about .413" to .416". The bullet diameter shown in Dixon for the 10.75x61 is 10.76mm, which is .424". Have you slugged the barrel ? If so, what is the groove diameter? Dixon gives 11.95mm as the maximum base diameter for the 10.75x61 and 12.10mm for the 9.3x62. The 11.95mm matches the base diameter of the M88 case, rather than the 9.3x62 case. Since the 10.75x61 is virtually a straight case without rim, it seems advantageous to use the largest diameter case that will actually chamber and the smallest diameter bullet that would give acceptable accuracy . This would give the best chance of holding the headspace. Since I shoot and load for a 9.3x62 , I have no doubt that a 9.3x62 case would enter a chamber cut for an M88 base case. Jacketed bullets can be sized a limited amount ( I generally try to limit this to .005", but for this size bullet might increase this) if it would help with the headspacing. If you are going to handload for this rifle, I think you have a fun project. As far as who actually built the rifle, I think J P Sauer and son would be as good a guess as any, but wouldn't bet the farm on it.
Mike

[Themauserkid]

Thank you for the input sir, my primary question is in regards to the maker. I need to take more pictures under the wood line when I have it apart next, to look for any other clues to present. Sauer Mausers are one of my main focuses, and I can?t personally see any similarities between the two.

I hope to load for it one day in the future, sounds like a lot of fun. The bore and groove are as follows:

Bore: (.4022)
Groove: (.4203)

Interesting indeed, the DWM listing has it as P?rschb?chse Kal 10.5 Haenel. It sounds like the Gentleman experimenting with the 9.3x62 case may have missed the detail on the base dimensions. Thanks again for the input,
Clay

[mike ford]

Themauserkid,
You have the rifle "in hand", and seem to specialize in Sauers, so your guess is likely better than mine, regarding the maker. My guess was based on probability, not hard evidence. Kettner bought from makers that gave the best deal for the products they needed. Sauer sold a good many different guns to "the trade", many of them based on commercial Mauser Oberndorf actions (such as yours), before the end of WW1 ( after the war, cheaper surplus actions were everywhere and many other makers could compete with Sauer, using Mauser 98s instead of M88 actions). Sauer was known to chamber for unusual calibers, on request. None of this is definitive however. A friend has an Ed. Kettner double rifle that was made by Sauer, and it is marked under the barrels with the so called "wildman" and the large and small Sauer crowns. Markings like these would be definitive, as would a small "S&S' on the muzzle or elsewhere.

You should be able to size custom made "cup and core" bullets intended for 10.75x68 to 420- 421", or you might find undersize 10.75- 404 already sized to .421". I don't think I would use jacketed bullets over about 350 grains, however, and would prefer 300. You might find it helpful to re-size 44 Mag/444 Marlin bullets to .421". I understand one of our other members makes bullets for his 10.75x63, this way. You might consider sizing them in two "steps" because you would need to take over .005". As always, cast bullets are another( and maybe the best) answer.

I don't think the gentleman helping you missed anything, rather it seems he was looking for the best fit. Listed dimensions are maximum for cartridges and if you had dimensions for chambers, they would be minimums. Manufacturers usually use somewhat smaller dimensions for cartridges and larger for chambers, to insure their products will work. Whoever was helping you likely had 9.3x62 cases on hand to take actual measurements from. More than likely I would have checked 30-06 cases, because I have more of them than 9.3x62, and would have wound up with a less acceptable fit than the 9.3.
Mike

[Themauserkid]

Yeah I don?t see any of the telltale signs of a Sauer on this one. Maybe this week I?ll have time to pull it down again.

On a side note, so far I have 7x57, 7x64, 30-06, 8x57, 8x60, 9x57, 9.3x57 and 10.75x68 recorded for Sauers. If anyone owns, or has observed an example in another caliber I?d love to add it to my study. I have yet to see some of the other calibers listed in their sales brochures.

Thanks again for the loading ideas, here are some dimensions of the chamber cast.

[mike ford]

It was only a guess that it is a Sauer, they usually had some sign that they made even the ones "made for the trade" . There were others that used commercial Mauser Oberndorf actions, just not as common as Sauer. Photos of the markings would help.
Mike

[Themauserkid]

Looks like I did have some pictures from the first time I took it apart. Action, barrel and stock have the same serial, no secondary assembly numbers etc.

[Themauserkid]

More pictures

[Axel E]

The commercial Mauser, Oberndorf, serial number 24572 dates the action only to 1908. As the placement of the serial number shows, he action was sold as an ?action only? to another gunmaker by the Mauser factory. The completed rifle was proofed in Suhl in 1912 for a service load of a steel jacketed bullet and a charge of 3.2 gramm = 49 gr smokeless rifle flake powder. It was proofed using the special 4000 atm proof powder. The gunmaker or individual gunsmith who built the rifle did not bother to apply a serial number of his own. He simply transferred the Mauser number to barrel and stock. As Eduard Kettner, Cologne, had their own workshop/?factory? at Rimbachstrasse, Suhl from 1910 on, I suppose the rifle was built there.

[Themauserkid]

Thanks Axel, I was under the impression that their Suhl address was only a means of advertising for Kettner before the Dornheim takeover, perhaps there was more to it though?

Studying the traits of other Ed Kettner marked Mausers might help identify some trends.