I found an answer here on TFL for you...
I copied this from another user, which I'm glad I read since I recently purchased a Mossy Maverick (has the safety in a better place than the 500 IMO).
First Mossy is over 22 YO and has well over 15k rounds through it. Still running strong. It's part of my home defense battery.
Second Mossy (835) is 18 YO and has over 10K rounds...still running strong. This is my waterfowler.
Third Mossy (20 Gauge) is only 7 YO and has around 2K rounds through it. It's just broken in. This one is my beater upland game gun.
Although they can be broken, one usually has to go to some extreme to do it. Just my experience.