AR bolts lock into the barrel / most bolt-action rifle's bolts do not - they lock into receiver abutments.
This si the part i was missing. THe bolt action I have studied the most is my K31 and I believe it also locks into the barrel, which is probably why it is so expensive to re-barrel.
I will have to look at my marlin 22(the only other bolt gun I currently own) and see how it is set-up.
People have told me that if I want a modern straight-pull rifle I should just get an AR and plug the gas plug. This has made me realize making a dedicated rifle off of parts might not be too difficult.