Each time you chamber a round from the magazine, the nose of the round hits the feed ramp. Repeated cycling of that same round is "hammering" the bullet back into the case. In effect, the deeper "seating" of that round will cause an overpressure condition when the round is fired, and could eventually become dangerous. If you reload, pull the bullet and re-seat and re-crimp it. I'd not fire the round that's seated too deep. Alternate which round you feed into the chamber.
Freedom has a flavor the protected can never taste...
USMC 8652, 2531, RVN Jun '67, - May 69