Re: 590 Mariner
I honestly don't know.. but the picture is identical to my mossberg 500 mariner...... must be some kind of engineering flaw I guess. Prior to use I put extra oil on that piece... but the good news is that it hasn't received any more damage other than whats in the pic.
Re: Mounting A Light On A 500 Tactical Cruiser/Persuader
I just mounted a light on my 500 and I love it! Take a look!
http://www.youtube.com/watch?v=UQ-yZDMwzPI
The picatinny rail screwed right in with ease into the existing holes that were pre- drilled and tapped.
As far as the rail under the heat shield; that was fairly easy as well to install.... now I just need a red dot scope for it.... but I just can't decide!