Firearms resolve hits against a targets touch AC at least within their first range increment. A gunslinger's 7th level deeds Startling Shot and Targeting can be activated on a hit and have no further save, combat maneuver check, or spell resistance. Given that you can easily flat-foot or disable an opponent for a round (via confusion, tripping, or the loss of their item) by only hitting their touch AC.
Granted, uses of Targeting is limited by grit, but this is easily overcome by Extra Grit, which gunslingers can take multiple times and with their bonus feats. Regardless, the ability itself remains tied only to a creature's touch AC.
This seems over powered to me. More objectively, is there precedent for disabling abilities such as these tied only to an opponents touch AC? Are there similar abilities or touch spells, attainable by level 7, which can disable an opponent without allowing saving throws or requiring a combat maneuver? Touch AC is generally a powerful foe's weakest defense, and these deeds seem exploitable all the way through end game.