I also purchased a locking grease gun tip as well as several adapters, zerk tools, tap, etc... after years of fighting with them. A propane torch is a handy accessory, sometimes a little heat will open up stubborn zerk fittings. The grease dries up and blocks the passage. I keep a variety of fittings on hand. I actually have a “New Joint” kit, which is a polymer injection system that repairs various joints like tie rods, etc by injecting a polymer into the joint through the grease passage. It was a specialty tool that a friend was marketing years ago. It works awesome, but never really caught on. I have used it to repair hard to find stuff on old tractors, etc... I’m still looking for the perfect grease gun that doesn’t leak between uses... till then, storing them in a five gallon bucket works to contain the mess.