For the past 17 years, I had been using a big old herky grease gun to keep the bearing buddy / wheel bearings well lubricated on my boat trailers. This year I finally decided to get one of those small hand held guns that use the small cartridges to apply the grease to the wheels when needed. I can't get the darn litle grease gun to work. I put in the cartridge as directed, puncture the foil seal, withdraw the plunger and so on... I get about 4 or 5 good shots of grease out of the head when the handle is pulled and then nothing else.. no matter what I do. I took the gun back and got a new one and the same thing happened.. It must operator error (me) as it just won't work. Anyone have any experience with these little guns or have the same problem? All comments will be appreciated...