The US Navy Lewis Gun is much harder to come buy than the 303 Lewis. A BSA Drum can be had for $200 in the US. The 30-06 Drums are very difficult to find here. When you do than can run $x what a 303 drum costs. I was lucky to get 3 fully functional drums when I got this Lewis. The pouch on the floor holds two drums. This Lewis has never missed a beat and is a pleasure to shoot. I hope you enjoy this old warrior.