A couple two or 3 years ago there was a bad batch of springs sold to Mossberg. Seems most complaints were on the longer tube equipped guns. Several of these guns made it to discussion here at TFL and a swap with wolf was the fix for everyone. These bad springs were easily identified by removing it... if it lays straight it is not a bad one. the bad ones had kinks and bends. Not likely that bad when installed but after a guy tries to load full capacity a few times, that little bend resulted in kinks and such.
As for me... The same spring and shell follower for way more than 20 years. I cannot, for the life of me (no pun intended), figure out how this wimped out spring works for the last shell or 2... WAY FAR LESS THAN 1 pound on that last shell... Maybe an ounce or 2 resistance...
Brent