Laminate stock - sanding and fitting

[EZM]

I just got a Boyd's stock for one of my Weatherby Vanguards and had to make modifications to allow the bolt to lock down (the cut out was ported a little toward the front and should have been cut out closer toward the stock). This was no big deal and 5 minutes with the Dremmel and a bit of sandpaper to finish off.

The other thing I noticed - the barrel seems to be "tighter" toward the left side (opposite of bolt) and the receiver is ever so slightly proud (high) on that same side when the action is seated and tightened to 30lbs. That's an easy sand and fix.

It's the fact that the receiver won't seat evenly is whats driving me nuts .... so I have been sanding, fitting, sanding, fitting and just don't know exactly where it might be binding or hitting - is there an easy way to see where it's hitting?

I also don't want to sand the wrong spot and make it worse.

I though about modelling clay, lipstick but don't want to make a mess that I will be cleaning up 12 months from now.

Any thoughts?