Re: Lug Lapping question---
Remove the firing pin. If the rifle is a Ruger, Remington, Savage, etc., it is not difficult to take out.
For a low-budget lapping tool, take a case that fits your rifle(.223, 22-250, whatever you are lapping). Cut the case in half and get a spring from the hardware/building supply store. Put the spring in between the two halves and use it to provide the pressure on your lugs while you lap'em.
The spring I used to use was bought from a hardware store and looked like a little version of what would go on a screen door.
david