What's the noun for recoiler? Here's the word you're looking for.
recoil
A starting or falling back; a rebound; a shrinking.
The state or condition of having recoiled.
(firearms) The energy transmitted back to the shooter from a firearm which has fired. Recoil is a function of the weight of the weapon, the weight of the projectile, and the speed at which it leaves the muzzle.