Re: Sprinfield 1903 30 06 problem
It sounds to me as if it is time for a meticulous chamber cleaning with a .30-06 chamber brush and a good bore solvent. If the entire chamber area inclusive of the cartridge neck portion is not squeaky clean attempting to close the bolt on a standard cartridge can exhibit symptoms such as you have described. Essentially, the round is not able to easily fully chamber which is giving you the heavy final bolt closing resistance that you feel. If you have changed to a different ammunition, go back to what worked well as there are sometimes ever so minute differences between brands of cartridges. Additionally, if the hard cycling round in question is a reload, the sizer die make need some adjustment to get the physical dimensions of the reloaded round to chamber correctly. But in any event, a good chamber cleaning is definitely in order.