I was using Mantle, however, Mantle causes more crashes after the 6th of march update, so I reverted back to DX11 for the time being.
I see, they're most probably going to fix it in the next driver update or so. Usually driver updates cause less crashes, more stability and better performance, but that can vary. Downgrading is rarely a solution or suggested for that reason alone.
Also, if you overclock you might want to remove it or try to change it a bit for the game. My GPU takes the overclock like a beast but in certain games it just does not work. (TF2 for say)
I would also advice tinkering with the OS you have. Downgrading/upgrading windows. You don't need to fully delete it, just set it on another section of your HDD or on a new HDD for sheer testing. I've heard that windows 7 experiences less crashes than 8 and especially the latest windows 8.Something.
Though in all honesty, all you can currently do is hope for yet another patch and possibly a driver update/quickfix. You can also go to the AMD forums and ask the people there what works best for them.
I don't OC, and it's deffo not my OS that is at fault. It's the march 6 update, things were running just fine before that.
March 6 update; Crash when try to change weapons on engi class on certain maps. Random crashes related to video rendering in Mantle, disappearing HUD in HC mode, disappearing info over team mates heads in HC mode, no kill cards in HC mode, occasional sound disappearing bug, etc.