A firearm cartridge with a rimmed metal case having a body portion having a rim and a cylindrical wall portion adjacent to the rim. The body portion has dimensions corresponding to a 22 Long Rifle specification. The case has a tapered shoulder portion contiguous with the first portion, and a neck portion contiguous with the shoulder portion and a defining a mouth. The mouth closely receives a bullet having a diameter less than .22 caliber, and the case has a length significantly greater than 0.66 inch. The case may be formed with a neck that is relatively short compared to the body portion and overall length, to provide improved cartridge trajectory performance.