6.5 mm german drilling 1920's - unknown cartridge



I have a German Drilling gun from the 1920’s 1930’s and i am trying to
figure out the riffling.

The numbers on bottom of the barrel for the riffling are faded.

What I can make out is 6,5mm (this is what the top number looks
The bottom number is hard to make out the first number may be a 5 or
it may not. The second bottom number may be an 8 or a 6 or a 0 or a 3
or a 5 (all i can make out is the bottom half of the numbers) . What
is clear on the bottom number is that at the end of the second number
it has “1/2” marked (a small
number 1 over a small number 2).
Also the S.t.m.G is 8gr.
The shotgun barrels are 16g. 2.5"

I suspect its a 6.5mm x 58R but the “1/2” marking at the end of the bottom number is confusing.

I intend to get a casting done by a gunsmith to determine caliber,
however I would like thoughts on what this caliber may be.
Any thoughts you may provide would be
greatly appreciated.

Thank you



While somewhat outside the purview of this forum, the best answer (other than what you got on the other thread) is to have a gunsmith make and measure a chamber cast for you.
From those dimensions we should be able to make a fairly accurate assessment of the “proper” cartridge for you (IOW we collect the cartridges themselves, but working off the chamber stampings is more of a firearm collector/shooter specialty).


See my reply to your query Re 6,5 Drilling under the "6,5 Arisaka Kynoch"posting, where it seems to have also been placed a posting of yours…I have made a full enough explanation.

Doc AV
AV Ballistics.