Is 7.62x39 ammo readily available at Dick's Sporting Goods or Wal-Mart? I ask because I am considering purchasing a Saiga or AK and if ammo is not available at those places I am going to have a hard time getting ammo because I am 18 and most on line stores require a buyer to be 21 to purchase ammo. The local gun shop overcharges too much on ammo. If it is difficult to find I think I'm going to have to go with the Saiga in .223 instead.