Awesome!
I dont know whats with you 'Old Glory' but it works fine for me (Hint: You Have to let the barrel spin for a few seconds, hello? minigun?)
Anyway I had enogh ammo (650) so I only had to reload it ounce in each day. But still 650 rounds in a single shotgun,SMG,Machinegun, or pistol? Those must be some big weapons. You should make a limit sor some of the guns what I mean is that you can still buy more ammo but some of the guns are locked on a cerain amount like the pistol 30 rounds or shotgun: 24 something like that.
Still fun but like all defence games it got boring after awile until it reached lvl 40 XD.