... When the gun is shaken, should have a dampened rattle, if it sounds like loose parts rattling inside it needs grease. The grease is distributed by the parts contacting/working inside, so results are not immediate, give it a bit (1 pump on an auto type gun, 4-5 on a small tool type) use the tool and recheck/add more later. If you add too much the tool will bog, not a problem, it will work out though the exhaust. When properly greased the rattle should be somewhat muted and a small amount of grease/oil should constantly be visible at the anvil/bushing.
I had no idea that you supposed to grease the guns. I do however oil them after ever use. I have a Blue Point AT531 rattles badly, and I was thinking it was on the way out. Maybe I should try to grease it? It doesn't have any grease fitting, shall I open it up to grease it. What kind of grease do you use? Could you cover a bit details?
Thanks in advance.