The SG 553 is a variant of the SG 550, an assault rifle manufactured by Swiss Arms AG. First developed in the 1970s, the SG 550 was a successor to the Stgw 57 battle rifle. The SG 553 is an improved version of the SG 552. Released in 2008, the recoil spring was now wrapped around the piston rod, resembling the original SG 550, that addressed several reliability issues. Other versions of the SG 553 includes a long barrel version, one chambered for 7.62x39mm fed from an AK family box magazine, or one chambered for .300 AAC Blackout.