I have one long action M1999, and one short action. Both "cock on open". After firing, the rear of the firing pin is slightly recessed in the bolt shroud. After the bolt is opened, the rear of the firing pin protrudes from the bolt shroud not quite 1/8". When the bolt is pushed forward and cammed down the rear of the firing pin is extended another 1/32" or so. I am assuming the last bit of movement is the bottom of the firing pin cocking piece firmly engaging the top of the trigger sear. I also get the same 'final movement' (approx 1/32") with a Winchester M70 and two Rem 700's. All five rifles take a similar level of effort to close the bolt. I would not call it "significant".
