seem to be hitting even fewer ducks at longer ranges than usual.
Answer probably depends on what your "usual" load is. Comparing bismuth to something like tungsten-iron or Federal Heavyweight will not give you the same results at longer ranges because of pattern density and retained energy downrange. Even comparing bismuth to quality steel loads will give different results at longer ranges. Big steel pellets will often kill better than smaller bismuth pellets, depending on loads, chokes, etc. I have never liked bismuth, but I have a bunch of it that I will shoot up eventually.