Picked this up at the gun show over the weekend, and started doing some research on it. It was labeled only as a Schmidt Rubin without much information on it. Obviously, it had been sporterized, but I didn't know what exact model it was until I got home and started researching into it. Based on the serial number, this appears to have been originally manufactured in 1900. The caliber listed on the tag was 7.5x55 Swiss, but I noticed something when looking over the various proofing marks and stamps, and seeing where the serial numbers on the barrel and receiver are located. Wait a minute, the serial number on the barrel is mostly missing! Apparently, a bunch of these were sporterized ('Alpine Sporter' is the marketing term I've seen) by a company in the US some time in the 50s-60s, and many of them were re-chambered. Seeing the serial number on the barrel cut down seems to be a pretty dead giveaway that a re-chambering was done. I've read that these were typically either re-chambered to .308 or .30-30. I placed a re-sized .308 case into the chamber, and it appears as though it fits correctly (A longer 7.5x55 Swiss chamber would cause the .308 to fit completely flush). The bolt closes on the case, and the extractor is able to grab onto it. I'll be bringing this one to a gunsmith in the near future to confirm what I should actually be feeding this thing (assuming it's safe to fire). The rifling appears to be intact, and the bore doesn't show any obvious signs of pitting, so I'm looking forward to possibly taking this one out to the range.