Otto Bock drilling help with ID caliber and age

[bongi11]

bongi11,
In the first new photo, I see "S&C_ie and another mark that looks like something in a circle, but I can't tell where they are located for sure. I don't know what they mean. Maybe, Axel or someone will come to our rescue.
Mike

The picture is under the back side of the receiver.
Thanks

[bongi11]

Not sure what the deep mark is.

[Axel E]

Sorry, but no idea here. The "circled C" mark is unknown to me, just like the square punch mark. As "& Cie" is just another German abbreviation for "and Company", I first thought about Simson & company, but they usually used "Simson & Co.". Which one of the umpteen other Suhl "S" gunmakers had a companion and signed "S & Cie"???

[bongi11]

IMG_3090.jpg here is the slug from the barrel its a 7 groove making a pain to measure from what i get its .4360 groove & .4280 bore.
IMG_3093.jpg
IMG_3092.jpg and here is the chamber cast dimension and the oal of case is 2.500. Cant seem to find a match for the cartridge. Any help would be appreciated.

[Diz]

bongi11, I can only come up with two possibilities after a quick search. They are the 10.75x65R Collath and the 11.15x65R Express. However the Collath is listed in my reference with a .423" diameter bullet and the Rimmed Express shows a .446" diameter bullet. Both being not quite right for your bore diameter but the case lengths are just slightly longer than 2.50" also. There are others with better references than mine and perhaps there are other possibilities. I will keep looking. Thanks, Diz

[Axel E]

As the case length you give, about 2.5", isn't very exact, your drilling is chambered for either the 11.15x60R LK or the 11.15x65R LK "Drillingspatronen" = drilling cartridges. Both were originally black powder, lead bullet cartridges, quite popular before WW1. Both were originally loaded with grooved, greased lead bullets, .439" diameter, of 336 gr. The x60 took 62 gr, the x65 69 gr black powder. Later, "nitro for black" loads were available, using a soft, Tesco type copper jacket 270 gr bullet and 43 and 46 gr R5 smokeless respectively, velocities 1870 and 1935 fps. Useable cases can be fabricated from 9.3x74R brass. .439 - .440 bullet moulds are available, but otherwise you are on your own, as I know of no published load data.

[mike ford]

bongi11,
After a quick look, I think it may be either 11.15x60 LK Express or 11.15x 65 LK Express. In comparing chamber casts to cartridges, you can't have the same dimensions, the chamber ( therefore the chamber cast) has to be larger than the cartridge, otherwise it won't chamber. The difference in head diameters may be from .005-.010", and it is sometimes hard to determine where the chamber stops and the throat begins. Both of these cartridges were popular( the x65 more so) and both available at the time the drilling was made. I hope this helps.
Mike
It looks like Diz, Axel, and I were all replying at about the same time and came up with about the same answer.
Mike

[Axel E]

Diz, the 10.75x65R Collath was a slightly necked cartridge. As the chamber cast shows no neck, it is unlikely. The 11.2x65R Collath aka 11x65R aka 11.15x65R Express aka 11.15x65R LK aka 11 mm Drillingspatrone 65 lang are all the same cartridge. .446" was the diameter of the stop ring, not the bullet body. The later Collath / Tesco case merely had thicker case walls to reduce powder capacity for use with the Tesco bullets and early smokeless powders.

[Diz]

Axel, thanks for your response. My reference does not show a shoulder of any kind on the Collath cartridge so the drawing may be in error and I have made a note of it. With that information I believe that it is the 11.15x65R or one of those designations. Regards, Diz

[bongi11]

IMG_3098.jpg measurements are real close.

[bongi11]

Here is a better picture
http://www.municion.org/11/11_15x65RStahl.htm