Man, if you can think of somthing sombody did'nt run down the barrel of a gun, you would have a shorter list, just a couple off the top of my head, let's see there people that have tried wood'en bullets, ice bullets, Frozen meat bullets, just about every kind of metal known to man, concreat, plaster,glass, who know's
If you are getting into reloading and have a shotgun you use enough to justify reloading it is very basic easy and enjoyable, and I like to think I'm saving money, but somtimes I wounder!!! It's what my dad started me on first, and what I started my son's on first, the best advice I can give you is to read everything that you can get your hands on first, and always use loading charts that are currant, The world is full of people that were not schooled correctly and are missing body parts, and some just plain old dead, once you have a load that you are interested in double check it with somone that really know's what they are doing, for instance if you load a rifle cartrige with let's say pistol powder, It's all over bro!!! Hope this helps.
Let's see, Full metal jacket, Steel Core/copper jacketed, Bi-metal/Cupro nickel jacketed, Solid Copper (Barnes), Winchester combined technology (CT) Lead/steel/copper jacketed Failsafe, Solid bronze..... The list could go on and on.