I hope you're not using cheap FMJ as your defensive ammo, but since the bullet is set so far back, I'm guessing you do. Yes, the setback is due to you chambering/dechambering it too often.
Change ammo to a decent JHP (Gold Dot, Federal HST, Winchester Ranger, Hornady Critical Duty) and create a special pile of ammo that you've chambered 15 times.
That amount of setback is EXTREME. I have never seen it that bad before. That'll amp up the pressure a lot. Not safe.