Is there any way to accomplish this? I ask because of the Whip-shot Deed Feat, it lists Amateur Gunslinger as an interchangeable prerequisite with grit class feature... but to my knowledge Amateur Gunslinger only allows for a 1st level deed... and since the Whip Shot deed requires the 3rd level deed Pistol Whip, I'm not sure if this is just a case of bad editing or if there is something I'm missing that can be used to gain higher level deeds with Amateur Gunslinger...
If this is possible, then it will greatly help out with a character I'm playing in a campaign, since the Gunslinger Class itself is not permitted in this campaign, but early firearms are as is the Amateur Gunslinger feat...
There is a specific cavalier archetype (I can't remember which right now) that let's you get higher level deeds with "mature gunslinger if I remember right l.
Edit: Found it, look at the spellscar drifter. There's at least one example of using amateur gunslinger with higher level feats.
Well I guess that is an option... though I still wonder if there are others... 9 levels of cavalier is quite an investment for a single 3rd level feat...