Story is: my brother and I inherited a Remington model 1867 rolling block from our grandfather. It is in great shape and we would like to see if we can find someone who can custom make ammunition for the weapon. Best we can tell is that it is in 12.17x44r. I recall seeing a video on YouTube explaining how to make the cartridge but neither of us are handy enough to want to shave down casings and such. Any suggestions/recommendations?