I have a mossy 500 and it is a great gun.
I took the red dot off and I am replacing with a reflex.
It has a Knoxx stock with a shock absorbing system. I took a class last summer and we shot 00 buck and slugs ALL day, and it was like shooting bird shot.
I am replacing the current stock with one of these that has the same shock absorbing system;
http://www.knoxx.com/NewStyleKnoxx/Prod ... Stock.html