I have a 24" 7.62X39 Encore barrel. I have shot Wolf steel cased ammo in it, had some FTFs until I put a stronger hammer spring in it. I didn't like shooting bullets that were both oversize and steel with a copper wash. I solved that problem, pulling the 311s and loading 308 Sierra 125s. I got a Lee factory crimp die and shoot to my hearts content. It will be more accurate, handloaded in a brass case with the 308 diameter bullet of your choice. As previously stated it is almost boring to shoot.
FM