Correct, the tip on the left. I've always used grease meant for front end lubrication so I don't know how to answer your question about storage. You could flip the direction of storage periodically to avoid the mess of removing and re-installing the cartridge. You'll notice the tiny steel ball set into each grease point. The needle has to be small enough to push that spring loaded check ball (have no idea how they make the darn thing) open. Having the pump action work with one hand is a plus--you do have to put some pressure behind the needle to get the grease in. - Dave