Thanks for explanation. I get my bismuth from a local guy (Lund) here in MN who makes the stuff up for custom order. I have shot it for a few years now mostly in my Wesley hammer 10 ga for ducks and geese. My range is more in the 40 yard category for the gun is not tightly choked. I have quite a few bismuth recipies so have stuck to them. I might try a tighter choked hammergun in 12 ga this year. Most of my hunting is out of the boat over decoys for ducks.