That sounds really great to me. How do you pack the empty shot cups into the field?
Years ago (many) when I was doing lots of ML shotgunning and there wasn't much info around, I read about and used a solution that was simple and worked really well, but was about as far from "authentic" as you can get:
Use plastic shot cups intended for shotshell reloading and overshot-cards. The author claimed and I confirmed that with the original shot cup you get darn near full-choke patterns from a cylinder bore, but if you cut the petals on the cup to about half-length you get modified patterns, 1/4-length gives improved cylinder, and removing the petals entirely give something between cylinder and skeet 1.
You could carry unaltered cups into the field and cut them to length when loading, as conditions dictated. In my 12 gauge double a full-length shot cup and 1 1/4 or 1 3/8 ounces of 4's or 5's shot better than I could hold out beyond 40 yards, and with standard powder charges, really whacked mallards when you managed to overlap the pattern with them. I used half-petals in the right barrel and 1/4 petals in the left for really nice Modified and Improved Cylinder "chokes" out of my cylinder-bore double 20 for snowshoe hare.
If I were to use these again, I think your idea of putting Oxyoke patches over the powder charge would be a real improvement, because there was quite a bit of fouling with the plastic cups by themselves.
Not saying this is as good as what you came up with, rather that it worked when there was not much else to go on. Instinctively I like your idea a lot better than packing a pocket full of plastic wads.
Thanks for figuring out an alternative and passing along the results!
