Heya,
So if we go with the rules of the feat, then the answer is yes. But what are you trying to do? If you are a rogue trying to use guns, you might as well multi-class and then you automatically get that feat at first level along with Grit points. Currently we go by the standard rules concerning gun smithing. Which is you may craft your items at 1/2 off the cost of the retail price and that it would be 1 day per 1,000 gold of the cost of the item.