A friend of mine, who's fallen on hard times has recently been selling a few of his guns. Most were accumulated over the last 10-15 years. He's doubled his money, in most cases. Now, the ones that have been good "investments" are/were older guns (pre-1930s), in excellent original condition. He likes Winchester lever guns, so that's the bulk of his collection. When he bought them, he already knew which ones were rare and/or desireable, and knew he was getting a good price when he bought them.
In short, I think it pays to do alot of research and specialize in certain types/models/brands, and know when you're getting a good deal. I don't think there's very many "new" (less than 30 yrs. old) guns that are gonna appreciate very much in value (some have already, but i don't see them going much higher). (Some of the current "cheap" milsurps may go up some, as the supply dries up, but not by a whole lot, as most are too common.) Stick with the guns that are already "collectible" and at least relatively rare.
If it were me, and I had substantial amounts of cash, I prefer some of the old double shotguns like Parker Bros. and L.C. Smith. In fact a friend of mine just inherited 4 guns which she asked me to research and "appraise". 3 were nothing special, and in poor condition (well, one of those could be worth a bit, but would take more than its worth to restore). HOWEVER, the 4th gun turned out to be an 1898 manufactured L.C. Smith, Model A-1. when I researched it I found that they only made 738 of this model, from 1892-1898. While it wasn't in great shape (poorly stored), it was decent(no rust or serious wear, engraving still nice and sharp), and the engraving was incredible. There isn't a single part (including screws!) on this that wasn't engraved (by hand!). We took it down to Doug Turnbull Restorations (where my other friend has had lots of work done--incredible place, incredible workmanship, and just down the road from me.) and they quoted $7000 for a complete restoration. Sounded like alot of money EXCEPT the only other A-1 I found for sale was $18,000! If you could buy this one (it's not for sale, being kept as a family heirloom) for a reasonable price, you might almost double your money, real quick. But, of course, the market for high-dollar guns is smaller, but there's still enough people looking for these types of things, that a really high quality, rare gun will probably sell. Hard to say if the market will stay there, though.
