Gunslinger

The Gunslinger is an unlockable Wrench replacement for the Engineer. It is part of the Engineer Update and was announced on Day 4.

The Gunslinger appears as a robotic fist. It allows the Engineer to perform a combo attack, in which the third strike with the fist becomes an automatic critical hit. The Gunslinger also gives the Engineer an extra 25 max health.

Using the Gunslinger allows the Engineer to build Combat Mini-Sentry Guns instead of the standard Sentry Gun. These Mini-sentries only take 2.5 seconds to build, and cost only 100 metal each, but cannot be upgraded or repaired, and only deals half of a normal level 1 Sentry Gun's damage.

Taunting with the Gunslinger will make the Engineer's robotic hand turn into a spinning cutter that stuns and kills.

Trivia

• The Gunslinger, as with the Frontier Justice and the Wrangler, appears to have been designed by Radigan Conagher, the Engineer's ancestor. This is shown by a hidden link in the Engineer Update. It also appears to be placed over the mangled stump of Radigan and the Engineer's arms. Valve's own blog post furthered this.
• The Gunslinger is more or less a reincarnation of the P.D.Q. item from the closed beta, both sharing the ability to build sentries faster, but are unable to upgrate them.