I would save up a little bit more money. The r9 380 IS AN UPGRADE, however the price you pay is not worth it. You'll get just a little bump in performance.
It's better to go jump up to say an r9 390 or r9 290/GTX 970. You will get your money's worth.
Also you can wait for r9 380x to release and see how that performs
It most likely won''t be a bigger upgrade than say to a 390, but perhaps when it launches it will be a huge success.
Also if you're not getting the performance you want in games you can try to overclock a little bit. I would not reccomend a large overclock with over-volting if you have no experience with it. A small overclock could net 1-4fps, depending on your situation.