I have had 3 inch remington express fired through this weapon for years. I thought I'd pick up some of these 3 inch PDX1 .410 defender shells from winchester for home defense. I put them in and could not close it up?? I put in the 3 inch remingtons and no problem? I'm stumped, please help me understand what is going on. Oh, and by the way, anyone want to buy a box of 10 of these nifty home defense rounds? Cheap? I'm not sure it is worth it to me to take gun and shells to a gunsmith. I'll just dump the hot loads.