I need help setting up my vice square on my mill more accuately. Normally I put a dial test indicator in the chuck and use a bungee cord to lock the rotation of the spindle by way of the Bridgeport Spindle Brake, here's the type of indicator I use http://www.wttool.com/category-exec/category_id/17411. For setup I find a point on one end of the fixed jaw of my Kurt vice, zero out my dial test indicator and zero out Y on my CNC DRO, move back from the face, go to the other end of the vice jaw and go in to my CNC DRO Y Zero and adjust the vice until the dial test indicator reads zero. I lock the vice in with about 110 Foot pounds on a Toqure wrench and check again, I keep doing this until it's perfect.

The problem is even though I've recently run a diamond stone over the jaws and they feel flat if I move the indicator over 1/4" it will read that it's off. So I don't know what I should be doing and what points on the jaws I should be testing to get the vice square to the mill. Any help would be apprecaited getting it setup more accurately.

P.S. What tool can I use to drill and tap into the top of Kurt Jaw, I think they are hardened, I want to make a permanent work stop.