Gun trading over the web is 100% legal, as long as you follow all relevant local, state, and federal laws.
Usually, this means that any firearm you buy from out-of-state must be shipped to a gun dealer with an FFL (Federal Firearms License).
Shipping guns you buy online is also a concern. For more information on gun shipping, read Shipping Firearms from American Handgunner.
Gun Auctions
GunBroker.com
GunBroker.com is an online gun auction where users may buy and sell guns, air guns, knives and swords, archery, and gun accessories. Our extensive FFL Holder Network helps you legally transfer your gun purchase. Huge selection, register and bid for free!
GunsForSale
Online gun auction with no listing fee.
A-Gun
Online gun auction for the firearms community.
EBang
Online gun auction.
Auction Arms
A-Gun Auction
Antiques, Curios & Relics, and Modern Guns
Online Gun Classifieds
GunPost.com
Not a gun auction, but an online gun classifieds system.
GunsAmerica
The Honor System Gun Classifieds
E-Gun Classified
Totally free online gun classifieds.
SubGuns.com
Classified ads for firearms and NFA weapons.
Shotgun News
Read classified ads, find a gun show or dealer, subscribe to or advertise in Shotgun News
Heavy Metal Armory
Firearm and NFA weapon classifieds.
Online Gun Dealers
Century International Arms
AIM Surplus
Quality Surplus Firearms and Ammunition at a Super low price
Purchase these excellent books on guns at Amazon.com