The 38-40 uses .40cal bullets and probably lead in an old Winchester rifle. It uses large pistol primers and lower pressure pistol powder. Depends on if it's a '73 or '92 Winchester as to the power levels you can load to and what kind of shape it is in. the '73 is the weaker action.
Louisiana Gun has HS-6 in 1# bottles and H-110 but only 8# containers. We've had Varget for the last month. You looking in the wrong place. We also have several Ramshot, Winchester & Accurate pistol powders.
Bryan