Yeah the R9 380 is a pretty good card if playing at 1920x1080. It isn't until the R9 290/390 and GTX 970 cards the FX-8350 becomes a bottleneck.
The R9 380 4GB is about the sweet spot for that CPU. It should be able to play everything at medium or better settings (mostly better, some games like GTA V is too much for high/ultra) with a good framerate.