yep the angles are 45 deg top and bottom. the gaps in my Seekins piccatinny rail are .205" wide and the raised rails are.187" wide
when I made my base for my Sako I tried several differant formulas and ended up using .0053" for drop per inch.
What I did was setup the rail in the vise on a riser so I could start the cut at the back of the rail and made that my start point. I then set up a dial indicator to read .0000" at this end , I ran the table over 7.250" and raised the rail .0384" on the dial , this equals out to .0053" drop per inch of rail , this worked out good for me , I haven't tested it yet but the few folks I've talked to that make bases say it should be real close to the 20 moa I was wanting.
I have since made a couple rails for some Encore shooters and they are all tickled pink