Welp, I loaded them this morning and believe I discovered my difficulty. The 15 ga. hard card and fiber cushion wad work fine but the 15 ga. OSC is just a wee bit too small. I have a few hundred 12 ga/ OSC's and with a bit of dexterity I made them work. I also cleaned the inside of the case mouth with acetone and used Elmer's Tite Bond glue. We'll see.
Ed, I shoot quite a bit of BP in this drilling, it isn't Nitro proofed, and in several cartridge rifles as well as muzzleloaders. I guess I haven't outgrown Davy Crockett and Dan'l Boone or all my rondy and Longhunter years.
