Swapping bismuth for lead does not concern me. See this thread:
http://parkerguns.org/forums/showthr...&highlight=Wsf
I tested the same load twice: one test with 1.25 oz of bismuth and one test with 1.25 oz of lead. All else the same. I was not surprised when the velocity and pressure data were essentially the same for both loads.
What’s heavier? 1.25 oz of bismuth or 1.25 oz lead?
The difference in volume is easily accommodated with less fiber wad in the shot cup.
-Victor