If you are going to shoot much...time to start reloading. And if you are going to reload, only buy brass ammo. You can't reload the steel cases. And yes, I tried. It's not a good outcome.
For the price, buy the steel. Brass for a 7.62x39 is outrageous... Not going to reload the steel as it's berdan primer. I mean you can, but a serious pain in the @ss. And for what you can get the ammo for? It just as cheap to buy it.