I've seen claims that a hollowbased, 90 gr .45 bullet, cast of nearly pure tin, can be driven to 2000 fps in a 1911, with 12 grs of Bullseye. The guy says that 8 grs wouldn't even cycle the slide. The bullet was cast in a 155 gr swc mold,by Lee Precision. Lee liquid lube, sized in a Lee sizer (in a reloading press) .451" OD, hollowbased by a centerdrill in a lathe. Remington commercial cases, CCI mag pistol primers.