every time i pour a 1/8 or 1/16 ounce jig head the hook is lose inside the lead.  The castings are complete but hook just kind of slides back and forth in the lead.  Any advice?

A couple of things that will solve your problem.

#1 When you pour your jig, let the lead cool in the mold before you take it out for a few more seconds.

#2 Take the jig out of the mold by the sprue and not by the hook.

#3 When you powder paint your jig, and bake it, it will tighten everything up.

#4 Finally you can put a little kink in your hook.

Sand a little the area of the hook where the lead is going to be, many hooks have thin film of lacquer covering them, that lacquer no always burns away when it comes in contact with the hot lead so the lead is not really attached to the hook, sanding removes the laquer creating a clean rougher are where the lead can attach firmly.