Which riffle on which SIG SG 550 is based is a 5.56×45mm NATO assault rifle developed in the early 1970s by Schweizerische Industrie Gesellschaft?
SIG SG 540 The SG 540 is a 5.56×45mm NATO assault rifle developed in the early 1970s by Schweizerische Industrie Gesellschaft (SIG, currently SAN Swiss Arms AG) based out of Neuhausen, Switzerland as a private venture primarily destined for export markets and as a potential replacement for the 7.5×55mm Swiss SG 510 automatic rifle known as the Stgw 57 in Swiss service.
SIG MG 710-3 The SIG MG 710-3 is a Swiss 7.62 mm general-purpose machine gun (GPMG) designed and manufactured by SIG - Schweizerische Industrie Gesellschaft (currently Swiss Arms AG). The weapon was developed as a commercial venture primarily for export, since the Swiss Army had already adopted the 7.5 mm MG 51 GPMG (chambered for the 7.5×55mm Swiss Schmidt–Rubin rifle cartridge), produced by the federal arms factory W+F.