Thank you all very much!
Interestingly, my 1st choice would be to have a hopper into which you can dump 500 loose rounds and then it would shake, shift, orient, and feed. That would be a big machine that would require power and all sorts of other things.
The helical drums or mags do not hold enough rounds. Same with the "snail" mag. Those are fine for rimless center fire cartriges. Even rimmed, belted or greatly bottle-necked rounds can be handled up to a point by curving the mag, but that is limited to 25-50, maybe a few more, rounds when being push fed.
Yes, Jim, the trick is to make them cheap (as in low quality and price) enough to be disposable, but good enough to be "reasonably" reliable. That is why it would not be for self defense or combat use, only plinking fun. Every once in a while one might jam or break. If you are just out plinking, you can get your money back. I could not offer a "get your life back" guarantee for other uses.
To share just a bit more, I have determined that it would have to be a two part system. You buy a metal "shell" that includes the spring winder. That would be a one-time purchase that fits your gun. Then you would buy "refill" packs that would be thin plastic that would be preloaded and disposable. Insert, wind, shoot, open to remove empty plastic pack, toss (or recycle). My design would have to be machine loaded and you would mess it up trying to reload it by hand. There would be no reason to anyway. For about $2-$3 more than the price of a 500 round brick of good quality ammo, you have zero handling of loose rounds and zero pushing into mags.
My initial calculations are telling me that 475-500 rounds would be pretty large and that 250 rounds might be a better first target.
Thanks again for all your help and interest. If I get a working prototype, I don't even own a 10/22 so I will need some help there.