Well some of my questions are basics, and some are preferences. I have handled many break-barrel shotguns, but this is my first pump. It will be 80% HD, beside my glock. I've already got 00 buck for it. I see people taking about a 590, and a 590A1. I only see a 590A1 listed on their website. Is the difference only in the length of what people type, or is there an actual difference? The gun has a 20'' barrel and an equal length mag tube. I was looking for a longer barrel so I could take this to the fields for clays. I can't find any. Do they sell 28'' barrels for the 590? If not, does a 500 barrel fit? The gun only has the front bead sight and nothing in the rears. Should I worry about adding different sights? The receiver is tapped for a pic rail or sights. Are there any necessities that I will need and haven't thought about or don't have? Thanks from the SG noob.