Ray, from 500psi up to 3500 it took somewhere around 80 pumps. I am not a small guy, 6ft, 250lbs. The last 30 or so pumps I had to keep my arms straight and basically squat down letting my weight compress the pump handle down. I took my time. Good thing though, 20 shots just dropped the pressure 500psi. A few reviews I’ve seen says you can get about 60 full power shots before it starts dropping off. Oh and I have found several electric compressors rated for that amount of pressure. The ones I saw ranged from about 220 all the way up to a couple grand.