[fred cook]

The cartridge on the left is the very rare Winchester 70-150-900 centerfire round. The numbers indicated a bore of .70 caliber, 150 grains of black powder and a 900 grain bullet. While the case appears to be a necked down brass 12 gauge piece, it is actually a special case made to use a large rifle prime instead of a shotgun primer. I can't even begin to imagine the recoil this thing must have generated! Depending on who you believe, Winchester made either one or a very small number of double rifles based on their 12 gauge shotgun frame. It is thought that most of the examples of this cartridge have come from Winchester bullet boards from the late 1880s. As far as I know, no one at this point in time claims to have one of the double rifles or knows where one is located. Winchester did make a few double rifles chambered for the 45-70 cartridge but that, of course was a much smaller (.45 caliber vs .70 caliber) bullet.