Ah, you have credentials.  That's nice.  I've got them too.  The 550 series is derivative of the AK.  That you doubt this clouds your credibility as an editor. Read this .  I'm not the only one who thinks so.  Now, having had the occassion to compare my AKM, my SG 551, a dealer's HK G36C, and an friend's FNC, I can say from firsthand experience that the FNC and SIG are CLEARLY derivative.  The G36, however, is a completely different design based on the Armalite AR-18 (actually, unused Armalite patents). You love your gun, yes, but ownership of a firearm does not make you an expert on said firearm. The inch measurements stay as an aid to us 'rebels' and the AK reference stays.  If you disagree, you'll lose in mediation. SIG??? Maybe not now, but then again, Ruger isn't Ruger either, it's "Sturm". Have a wonderful day.