Buying guns and ammunition online can save you money. Be warned, if you're not careful you can end up paying more and getting ripped off. Before you begin online, make sure it is legal for you to purchase a firearm out of state and have it transferred to you.
Online Stores
A safe bet is purchase from a well known gun dealer such as Bud's Gun Shop. They sell hundreds of firearms each day and get their inventory at much lower costs than your average dealer.
Gun Auctions
Gun Broker and Auction Arms are the two most popular auction sites.
Online Classifieds
Guns America is huge online classifieds for anything firearm. Make sure the dealer has a good reputation in their transactions.
Gun Shows
You can get some great deals at gun shows. The best advice is to go knowing what you want. This way you can research prices and know if you are getting a good deal.