for head space they usually mill or grind the bolt face
some or most of the bolts are not square and this really helps
IIRC i have my head space at about .0445-.045 with firing pin protrusion at about .035 i would need to measure them for definite nos. but those seem to ring a bell
measure from the bolt face to the bottom of the cut for the cartridge head ,, stock,, it will probably be in the .050-.052 range
do not cut any less than .043,,,bad things could happen ,, slam fire ,, fail to extract ,, fail to feed ,, that one not so much but it could make it happen
if you do this you could see extraction problems,,doesn't happen all the time but it could ,, just a heads up,,,if it does there are some folks that sell a new extractor with the hook set back to compensate for the bolt face being set back,,,or you can rework the one you have to make it tighter
sometimes i have seen this and other times it doesn't matter much,,i haven't figured out just why some need it and some don't
this doesn't do much in the accuracy department,,maybe some, maybe not,, but it does help you get more reliable ignition
also you may want to bead the action,,or at least bead the front part where the acton screw holds the action and stock together,,i think KIDD has a kit to pillar the stock in that area,,might want to check that out later on
that's my .02,, hope it helps
ocharry