It depends on the action and how much play/room there is between the bolt and the inside of the action. Properly applied Cerakote is .001-.002" thick. Assuming that only .001" is applied to each surface you have added a total of .004" in thickness. If this is done on a custom action that had minimal bolt/receiver clearance to begin with, then it will be tight and cycle rough. I have felt custom actions with fresh Cerakote that were like this. On a stock Remington 700 action with more clearance to begin with it likely wont be as pronounced. If there is enough room for the added Cerakote thickness to begin with then the action can cycle smooth.