Re: How to smoothen bolt up?
before you send it out to be coated with NP3 (or similar) run it through a couple thousand cycles. Once you NP3 coat it, it will seal in any burrs and will take even longer to wear in. NP3 is an awesome coating, but it is very wear resistant, so make sure its slick before you coat it!!
if it is really gritty you can put a couple dabs of lapping compound on the lugs and run it back and forth in the raceway and twist it in and out of the breech a few dozen times, then be sure to clean all the compound out, re lube and it should be much smoother. The lapping compound will remove any burrs and machine marks that are rubbing against the bolt. Don't do it too much with the compound as it will take off more material faster then you think and then you will have a loose bolt.