I bought a few brands of ammo that I'm unsure about. They are 7.62 x 39 Wolf FMJ steel case, Brown Bear FMJ, and Hot Shot FMJ from Century Arms. I paid $8 per box of 20 a couple months ago. Does anyone know if these are corrosive? I also noticed that the Brown Bear and Hot Shot has lacquer coated cases. This stuff melts to the inside of the gun's chamber. Should I avoid shooting lacquer coated ammo? Why do they make lacquer coated ammo anyway?