I read thru that thread and one guy posted this:
"the first Mossberg 500's had to be recalled because they would fire when racked hard. It was because of a free floating firing pin that would hit the primer and make the weapon fire. They fixed that fast but some of you would have thought that was just great."
I don't think this is great! This describes my concern exactly. An uncommanded discharge. And if you accidently dropped it on the muzzle end, it could discharge for the same reason! They moded that spring in there for a reason! And also I believe my shotgun to be one of the "first Mossberg 500's" due to that very low serial #
Thanks for looking at this!