I know some folks refer to The Land of Almost Right, but this one wasn't anywhere near "almost". A couple of years ago at a sale I bought a spare air hammer (so it's too late to return it). Yesterday I finally fired it up and found that it hammered whether or not the trigger was depressed (which is a heck of a thing to discover, when you're holding the thing by the top and attaching it to the air hose). The way these guys work is that the trigger pushes a plunger that unseats a ball from a rubber seat. On this one, either the plunger was too long or the bore in which the seat sits was bored too deep, as the plunger held the ball above the seat with no pressure on the trigger. I put an O-ring behind the seat and all is well. But geez, don't they test these things -- even for a second -- at the factory?