What alloy do you guys use for casting .223 Rem bullets? I have a good half ton of clip-on wheel weight ingots and maybe 500 pounds of the stick ons. I cast .311s for my Garand out of the wheel weights with no leading problems (at around 2000fps). Would the same work for my AR? It's a 1-9" twist 16" barrel. I'm thinking that with proper sizing and lube (along with a gas check), wheel weights might be OK - I've just never cast for a direct gas impingement rifle, so I don't know what kind of gunk I'll be putting into the tube, but if the Garand is any indication, it won't be much of anything.