I bought a bunch of the 3 inch Black Magic Magnum slugs by Brenneke for bear defense. They kick so hard that my shoulder wants to go numb after 5 shots. I put them through my Mossberg 590 and the recoil causes the action to lock. I have to wiggle it as I pump it to unlock it. Is this normal? Will the 2 3/4 inch shells also do this? Is there a better round for bears out there?