I'm thinking about getting an 1100 with a 21" Cylinder bore that would be primarily for HD and range/fun. I already have a Mossberg 590 Special Purpose for HD, so really I'm already set and know it. However, this Remington 1100 Magnum with rifle sights looks and feels good. I just don' want to buy a problem gun. If I got it, I would want to add a Wilson 2 round mag extension. My questions are 1) Are these generally reliable enough for HD? 2) Will the mag extension change that reliability negatively? and 3) Is it true they don't cycle cheap bird-shot rounds reliably (thereby greatly diminishing the fun factor)? Any answers or other thoughts would be appreciated.