I have two 68 ci tanks, one regulated at 1800 psi and the other at 2900 psi. I shoot the Discovery tethered to the 1800 tank and the Marauder rifle and pistol to the 2900 tank. Never counted the shots with either, but never ran low on air when shooting. When tanks are full to 4500 psi, I've never shot any of the guns down past 2000 psi for the Discovery or 3000 psi for the Marauders. That's a lot of shooting.