I found an excellent deal on a Mossberg 590. It has some dings here and there (looks like it's been dropped), but I don't notice anything that seems to be a functional issue.
Right now it's configured as a pistol-grip only gun with a 20" barrel. It's got a bead sight and a heat shield. The pistol grip's going as soon as I can get Magpul furniture on the thing, and I'll probably take the heat shield off as well to save a bit of weight. Apart from the furniture, is there anything that should be done to the gun for reliability's sake? Replacing the mag spring/follower, for example? What about the trigger group and safety -- is there any compelling reason to go to metal for either?