Thanks all. I was sure it wasn't a new question
Michael: I completely understand your concern for the potential OP-ness of this particular combination, though I do have to disagree a bit on that stance. The really important detail is that a Free Action is required. While a GM that plays it a bit loose might allow multiple Free Actions during an Initiative Pass (due to SR5 p.163) I find that RAW and RAI it's not so scary as, according to that same page, you should really only get 1 Free Action during the entirety of an Initiative Pass.
Most gun-toting PC's are going to have 2 Action Phases each IP out of chargen. And according to Strive for Perfection if they are using their gun they HAVE to do a called shot "unless he is providing covering fire or acting in a similar capacity". That means the PC will generally do a called shot during their first Action Phase, using up their one Free Action. So, strictly RAW, during their second action phase if the PC wants to use their firearm they actually can only provide suppressive fire (and at a -1 die penalty due to Sharpshooter) since they don't have a Free Action to make a second Called Shot.
The only way I know to get around this is to also purchase Perfect Timing for an additional 5 Karma to get an additional Free Action each Action Phase.
And if you do THAT, then out of chargen you've spent 84% of your possible Positive Qualities around this one trick, which is not a small investment. So you should really get something useful for that investment.