I am new to the AK. I just bought a Bulgarian AK74 5.45x39 and need to buy more mags. I dont like just having the cheap one it came with. I am seeing that the Circle 10 mags are the way to go and are going for $30/$40 and up per mag. I am also seeing Circle 21 mags for a a few bucks less. They are both Bulgarian made correct? What is the difference between the two? Or is there any difference? Are the Circle 21 mags just as good as the Circle 10s?