I recently boght an old German made single shot rifle, no maker's name, hinge action.
Chamber cast and barrel slugging show it to be a 9mm x72R. This doesn't show up in Cartridges of the world.
Comments and suggestions please
jclayton

I would rather presume that it is a tight 9.3x72 R, which's diameter is narrower that regular 9.3 mm, means .364 instead of .366 inch.

Apparently in those old days, barrels were not yet standardized and sometime bored very narrow for "better precision".

How do the grooves look like, could it be cut for lead bullets?

Could you post a picture of that rifle?

i jclayton,

In my "Cartridges of the World" 7th Edition, Page 350 shows the 9.3 x 72R along with another 5, 9.3 x 48R, 9.3 x 57R, 9.3 x 70R, 9.3 x 80R, 9.3 x 82R and says this 6 can be lumped together as the only difference is the case length. it goes on to say that only the 9.3 x 72R survived the war and is listed in the late RWS catalogs.

Hope this helps,

Cheers from Australia

I think DUK has the answer. It must be a tight 9.3mm bore. The barrel has very deep rifling, which is sharp and clean. It should be good for lead bullets. Wish I knew how to post pictures since this piece has some very nice engraving on the action. Many thanks for your replies.
jclayton

The firm Haendler&Nattermann sells .364 193 grain lead bullets for this caliber.

The Europeans have slightly different ideas about the proper relationship of bore to groove dimensions/ratios. In addition, I would expect the bullets to be variable, because the 9.3mm refers to the bore (land-to-land) dimension and not the groove dimension.

Slug and measure the land-to-land diameter to find the caliber, properly, but still fit the bullets to the grooves, if possible.

Bullets that are nominally a small amount undersized or oversized, are usually not a problem