I searched an old homesite a couple of weeks back and was curious about this rimfire cartridge I found. Everything so far points to a turn of the century home, with the only coin so far being a late 1890's Indian Head. I found three 12 gauge brass ends stamped New Club, which from what I've gathered is pre-1911. The button on the left appears to have some type of fabric material in there, but I accidentally pushed the back off when getting the mud out. The rimfire is what has me stumped because it is larger than .22, but I don't know if that makes it a .25 or a .30 short. The headstamp is an H, or possibly an E, or possibly an F, but I'm thinking H, which would mean Winchester I think. I've included caliper pics, but since the cartridge is a little bent, I don't know if they will be conclusive. I also found what appears to be a lead slug from a very similar caliber, but it is flat on both ends and doesn't look damaged. I don't know if they made wad-cutter type rounds for the rimfire cartridges or not. I've done some research on the site, and there seems to be some very knowledgeable people in this area, but they all needed measurements, so I went and got some calipers. Any help would be greatly appreciated.