mass-produced. SG 510-4: 7.62×51mm NATO variant used by Bolivia and Chile. This version uses a shorter barrel and a buttstock made from wood rather than rubber. Overall length is much less than the Stgw 57 with a subsequently lower weight. The buttstock and stock tube are angled downward rather than straight inline with the receiver. SG 510-5: .30-06 Springfield (7.62×63mm) experimental rifle made for testing by the Mexican Government. SG 510-6: 7.5×55mm Swiss test batch of rifles based on the SG 510-4 in the Swiss military chambering intended to replace the heavier Stgw 57. The rifles were only built for testing and were no longer considered after 1980s trials. SG 510-7 T / SIG-AMT: semi-automatic only variant of the SG 510-4 imported into the United States in relatively small numbers. It was available in .308 (7.62×51). "AMT", term used after 1969, stood for "American Match Target". It was equipped with fine wooden furniture and could be ordered with a rounded upper handguard. Gewehr 2 (G2): 7.62×51mm NATO variant procured by the Bundeswehr for trials in 1956, which eventually lost to what would become Heckler & Koch G3. PE-Stgw. 57: (Privat Einzelfeuer) semi-automatic only civilian version of the AM 55 available in 7.5×55mm GP 11 Swiss. This variant is not the same as privatized former Swiss Army service rifles. It was specifically built as a semi auto only rifle along the lines of the Stgw. 57 with which it is frequently confused. While over 700,000 of the Stgw. 57s were built for military use, less than 5000 PE-Stgw. 57s were made. Users : SG 510-4 variant. : Used by the Compagnie des Carabiniers du Prince. : Adopted by the Swiss Army in 1957. Gallery See also SIG MG 710-3 SIG AK53 Sturmgewehr 52 References External links Modern Firearms Biggerhammer.net Schiessschule Walenstadt Swissrifles.com Gunco.net Exordinanza.net Euroarms.net Starting portal for articles, information and manuals, etc. on the Stgw 57/SG 510/AMT and SG 550 rifle series 7.5×55mm Swiss firearms 7.62×51mm NATO battle rifles Rifles of the Cold War Rifles of Switzerland Roller-delayed blowback firearms Military equipment introduced in the 1950s SIG Sauer rifles