Dude I don't know what happened last night, but I "dropped the hammer" and woke up with half a social security card and a 70's style Slazengertennis racket.
By Dione
Drop The Hammer
Holding nothing back. Usually refers to ending something.
The term comes from the hammer action on a gun. The hammerdropping on many pistols is what causes them to fire. If you "drop the hammer" on somebody, you go all out.
An idiomatic expression meaning roughly "to explode in a fit of rage and fury", it is derived from the action of a firearm hammer "dropping" -- or striking -- the firing pin which in turn impacts the round and causes the mini explosion that results in a bullet or other projectile being launched at a high velocity out of the end of a barrel.
The expression can be used in several different variations with the above definition: 1) ...part. in a draconian way 2) ...leaving a wake of destruction in its path 3) ...against a very specific target with precision; etc.
"I have a clear shot of the target. Requesting permission to engage."
"You have the green light. Drop the hammer on that motherfucker."
BANG. Bad guyfall down.