If you haven't figured it out its hard to beat a Remington 870. I bought a fully rifled barrel for mine and its shooting 3 inch groups at 100 yards no problem. I'm sure Mossberg 500 can be as good. I wouldn't get rid of mu 870 for nothing.

My 12 year old daughter shot it with no problem too. 12 Gauge... She's pretty tough though...LOL