What is that comparable to?

It's approximately .413" I can't think of any cartridges off the top of my head that use a .413" bullet. the .405 Winchester uses .411, and most of the .40 caliber black powder cartridges with which I'm familiar run from .408 to .412 for their bore diameters.

What is the question related to? If it a proof stamp for caliber, it could be the bore, the grooves or not really 10.5 at all, just near that based on plug gauges.

http://gavingardiner.com/BidCat/detail.asp?SaleRef=0047&LotRef=70

Probably something like the 10,5X65R Collath aka 10.75X65R Collath. Really need a chamber depth and chamber profile.

Serbus,

Raimey
rse

Could something like this be re-chambered to a more common and low pressure cartridge?

Nice gun. What is an "Artist's Resale Right"?

About all the other 10.5mm choices are those Teschner short 10.5mm target cartridges less the Beast Miller & Grieß 10.5mm Behemoth.

Serbus,

Raimey
rse

So how long is the case? What exactly is the bore diameter? Is it a straight wall case? My little Sauer driller wouldn't take a .44 caliber bullet. It turned out to be an 11.15 X65. This is a more common choice than some mentioned here.

Since this is a German rifle, it is likely shown as a 10.5mm rifle because it is marked as such in the proof marks, either directly in mm or in a gauge measurement that translates to 10.5mm. They were marked with the bore (not groove or bullet) as Raimey stated. The actual cartridge's nominal designation could be any one of several different ones, and not necessarily of German origin. To ID the cartridge, a chamber cast will be necessary, together with "slugging" the bore. Rechambering such a rifle is a poor choice, for several reasons, not the least of which would be the need to re-regulate it, even if it could be done safely. A much better idea would be to handload for it, even if you have to make cases and bullets from something else.
Mike

Solely from the foto & the description, devoid of sideclips and Greener Crossbolt, and considering the serial number 6060, it must have been made prior to 1880 and was for a lower pressure Blackpowder cartridge. It is possible that Sauer sourced it elsewhere, so the serial number could lie with another maker?

Serbus,

Raimey
rse

Since the description mentioned it is nitro proofed it carries proof marks, so it must be post 1893.
Mike

Either a reproof or they are mistaken on the >>Nitro<< and those ATM stamps or >>Nitro<< stamps may just put it circa 1910 or post 1912??? Possibly a proof effort on a pre-1893 DR??

Serbus,

Raimey
rse

Even >>Vorrat<< stamps do not appear till 41xxx in the Sauer sequence.

Serbus,

Raimeyr
se

It is not clear whether 6060 is the serial number or some type "item" number from the auction house. Maybe someone will buy it and show the proof and other marks.
Mike

Yeah Ford, for £600 plus $1200 U.S. of A. import costs, we could well know.

Serbus,

Raimey
rse

could be the 10.5x47r.

Mike,
The 47mm case shortened from 11.15x60R is a good possibility but if it is marked 10,5 the nominal caliber would likely be 10.75x47R. This was a popular case in lengths from 43mm to over 60mm. Beside the MB case other possibilities are the M88/ Lancaster case, 450 and 500 base British cases, or Colath/similar cases; but in my opinion the 360 base case is too small to consider. This is why a chamber cast and bore slug is necessary to ID the caliber.
Mike

If in doubt a cast is cheap and easy insurance.

And interestingly they also made ones marked 10.5:

The pictured rifle is not pinfire.
Mike

Concur with Der Ami completely, if you get the gun you will start your odyssey with a chamber cast and slugging the bore to determine what cartridge and bore size you actually have. Once you figure that out you will then begin the search for loading data if it exist, what case will work best, then get dies (CH4D is a good source), probably buy quick load software to help develop loads, and it goes on.


Listen to Der Ami, he guided me through a similar adventure with a Springer 10.75x52R double rifle I came by with great results.

One more thing if you can find it is the book “Shooting the British Double Rifle” by Graeme Wright, it provides invaluable insights into understanding the loading and shooting Double Rifles.

Thanks, old colonel for the praise, I don't know if it is merited, I just try the best I can.
Mike