Quote Originally Posted by Frozen_Feet View Post
Not really. Just add Saving Throw Vs. Death to guns in addition damage, or use rules for Massive Damage and lower the hitpoint treshold for triggering it to something that comes up reasonably often with guns.
Hackmaster has a "Threshold of Pain"; if you take more than that amount of damage in a single blow, you have to make a Trauma Save by rolling under 1/2 your Con on a d20p. If you fail (more than 1/2 your con), you are incapacitated for 5 seconds for every point you fail by.

It takes 10 seconds to Coup de Grace. It takes a multiclass thief 5 seconds; thieves can do it in 3, and assassins in 2.