I have been watching your thread for a few weeks. I would not recomend that. Due to the reason I do not see a logical purpose and the projectile flight would be less than favorable. When you would be just as well of with 00 Buck or number 4 Buck or similar rounds for Self Defense. I just don't like the idea of shotgun projectiles out of control in flight. I have done some experimenting in my day. But nothing ever worked out fantastic. I remember I had the idea that I could put 6ea 36 Cal. Muzzle Loader Balls in a 12 Ga. for fox hunting. But actually found factory rounds that out performed my fantastic new loads !
Even 12 pellet 00 Buck has at least one flyer at 25 yards normally. Only my thoughts! Then you at best would have to start with experimental loads which can be a disaster awaiting. Only my thoughts as I stated. I wanted to at least give you some response to your posted thread.