does anyone have any tips or tricks on hand loading a small grease gun. the only grease cartridges i can find for this gun is lithum and would like to try valvolines synthetic but cant find a small cartridge for it. the reason i have a small gun is that it dont take up a whole lot of space and i dont use it that often. someone told me i can hand load an empty cartridge, so i bought a jar of the stuff and am having problems loading it. it only works for 2 or 3 squirts and than stops working. any ideas? thanks.