'gun hammer' is not correct and usable in written English.
Instead, you could use 'hammer a nail' or 'hammer a gun' depending on the context. For example, "He carefully hammered the gun into the wall."
Working in broad daylight, and without the city's permission, Ms. Galland uses the tools and techniques of conventional upholsterers -- staple gun, hammer, pliers, tacks -- to stretch a piece of vinyl or Naugahyde over the top of the stump, trim it and finish it like a piece of furniture.
It's well known that the greatest defence against an intruder is the sound of a gun hammer being pulled back.
Attach ribbons at the top using a staple gun, hammer and nails or similar.
Get some stuff that can damage it (e.g. Bat, BB or pellet gun, hammer, keys, nails, stomping on it, whipping it at the floor) Work your muscles!
He mowed them down, picking off carton after carton, and when he ran out of bullets he grabbed the hot barrel and beat the last few milks with the butt of the gun, hammering away until the seams burst and the waxed cardboard turned to pulp.
As the industrial cacophony of Portishead's Machine Gun hammers its way across Suffolk on Saturday night, the stage flanked by two monster-sized images of David Cameron, lasers instead of eyes, you can't help but wonder if there's a more jovial way to celebrate a birthday than a stark reminder of austerity Britain.
Bob can draw a gun, cock the hammer, level the barrel, pull the trigger, & fire in.0175 of a second.
Signs were also difficult to put up, requiring effort, staple guns, hammers and some physical labor.
People really get hurt in this book -- fists, guns, hammers and bombs are among the weapons of choice -- and Corbett writes with an intensity of feeling that doesn't gloss over their pain.
Inside were a Taser gun, meat hammer, skewers, zip ties, cleaning supplies and a dental retractor, according to the criminal complaint.
In his decision on the computerized video, Judge Coleman barred a portion of the video that shows a stray wood chip interfering with the normal operation of a gun's hammer and firing mechanism.
