Question: 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?
Sentence (from "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.
Relevant evidence: Yes