I have been using Bismuth for years in both modern shotshells and in my soft barreled muzzleloading shotguns (too soft for steel that is) for waterfowl hunting. It all started when lead was banned for waterfowl, I had a roomful of Federal lead 2 1/4 oz loads for a ten gauge. I discovered that I could pull the lead shot, replace with Bismuth same size, replace the filler and get great patterns and distance. It turns out that the space needed for 2 1/4 of lead is exactly 2 oz Bismuth. The lighter load shoots a little faster, slows a little quicker becaause of lower BC, but seems to function the same. This prompted me to use it in other muzzleloading shotguns, especially the precious antiques (I won't own an antique unless I can shoot it) I use the same weight, which means 9% more volume, of Bismuth as I ordinarily would lead. Seems to work about the same, functionally can't tell any difference. It makes a duck or goose expensive, but it's far better than leaving the muzzleloader home. DOC