I took Chads advice and I have measured several times more than twice I have to drill out the pillar holes and set them so my stock in exactly 1/2 in 1/2 out but I am nervous about cutting the rear hole...not much room to play with
Re: getting ready to mill my last cuts in my stock
If your stock is synthetic then HAVE NO FEAR. Seriously. It's near impossible to ruin a synthetic stock. If you eff it up, mix resin, baking soda, and fill your goof back up.
It's as much about fixing mistakes so you can't see them as much as it is avoiding them.