One of the most common subjects of debate in the world of the firearm enthusiasts is: Which is better, the 556 NATO or 762x39mm cartridge? GunBroker.com provides users with a convenient platform to buy and sell both calibers, and almost any other firearm, ammunition caliber, part, accessory, optic, and much more. Read on to discover some of the rifles chambered 762x39mm that you could find from sellers on GunBroker.com.