I signed onto the forum because I have a Mossberg 500C in 20 gauge. It was a gift from my son for use as a home defense gun and has a pistol grip mounted. I'm interested in taking it out into the field for pig hunting now. I want to find a good butt stock, maybe one that carries extra shells. I am guessing that the 500 series parts interchange, but hope to find out for sure here on the forum. Any advice on what to add to it to make it more user friendly as a slug gun would be appreciated.