I just learned the difference between these two and now Im totally sold on this rifle. Relatively obscure round though from what Ive seen in the ballistic tables, the 5.45x39 is definately capable IMO. Plus, INEXPENSIVE!!!! 1000 rounds for $150, unbelievable. Some one tell me Im smokin crack and this isnt real for some good reason, or if you have this rifle, let me know about your experience with it.