Mauser 1893 .22

I recently picked up an all-matching Mauser 1893 in good shape which has been converted to a single-shot .22. I'm not very knowledgeable when it comes to Mausers, so I figured I might try to get a little more information by asking on the forums.

The barrel itself appears to be a .22 barrel and not a relined 7mm barrel.
Attachment 118003

The receiver has been ground away to facilitate insertion of a .22 cartridge, exposing one of the locking lugs.
Attachment 117997

The bolt itself has been modified to be able to extract .22 casings.
Attachment 117998

Interestingly, it doesn't appear to be chambered in .22LR. A .22LR case gets stuck halfway in the chamber. You can force the bolt closed, but the .22LR will get stuck in the chamber and after poking it out you can see rifling engraved on the top of the brass. While I have no .22 Short on hand, a .22 Ramset blank (which is pretty much a .22 short) will insert and extract as normal.
Attachment 117996
Note that the original 7mm follower is still in place.

I have no idea if this was done by the military or is just another example of bubba at work. If you need any more information, feel free to ask.

interesting rifle, will it pick up and feed, or do you have to manually feed the rounds?

The magazine has not been modified, so cartridges have to be inserted into the chamber by hand, but they extract just fine due to the bolt modifications.