This location is where I will keep feats that are worth having but not within the core books. I was going to put a complete list here, but with over 3000 feats in existence just in WOTC products, I decided against that.
Pistol Whip
Page 154, Sword & Sorcery's World of Warcraft setting
Benefit: You are proficient in the use of a firearm as a melee weapon without damaging the weapon or incurring penalties. A firearm used in this way deals bludgeoning damage dependent on size:
Firearm size Damage (S) Damage (M)
Pistol 1d3 1d4
Rifle 1d6 1d8
Field Cannon 1d8 1d10
This feat may be selected as a warrior bonus feat.
Bayonet Charge
Iron Kingdoms Setting
Prereq: Dex 13, Dodge, Mobility, Point Blank Shot
If armed with a loaded firearm and using the Charge action, you can fire the weapon at point blank range and make a charge attack with the bayonet, provided you may reach the opponent on the charge.
Exotic Weapon: Small Arms
Iron Kingdoms setting
EW:SA allows you to take up firearms of pistol or rifle configurations and use them.
This feat may be taken as a warrior bonus feat.