The SG-552 "Commando" is a very compact assault rifle of the same class as Russian AKS-74U or German HK53 and G36C. Due to the short barrel and resulting short gas piston rod, the main spring in SG-552 was relocated to the receiver, behind the bolt carrier group, so the bolt carrier of the SG-552 is not 100% similar to the bolt carriers of the SG-550 and 551. All SIG-550/551/552 rifles are equipped with semi-translucent plastic magazines that can be clamped together for faster reloading.