I live in California and we now have to use non-toxic shot. I've narrowed my preferred choices down to Bismuth and Tungsten-Matrix. Bismuth is more economical and looks heavy enough, but my concern is its supposed brittleness and tendency to shatter compared to other materials. It might be OK for ducks, but I don't know about a tough old gobbler. Any experience with Bismuth --- acceptable for turkey, or should I steer clear? And if Bismuth is acceptable, would T-M still be the better choice? Thanks.