Re: headspace question! help!
You wont know till you get the parts put together. DONT assume that if the bolt closes with a cartridge in the chamber that all is OK. You will need to employ the use of a go/nogo guage to know. Too much headspace will cause case head separation. No way to tell till you guage it. If in doubt, take it to a competent smith. If there is too much space the barrel will need to be set back a tad. If there is not enough, then a reamer will need to be used to cut it deaper.
Long range shooting is a process that ends with a result. Once you start to focus on the result (where the shot goes, how big the group is, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.