In the 1940s–1950s, the GN received surplus American infantry weapons of World War II/Korean War-vintage – M1/M2 US .30 carbines (7.62×33mm) and M1 Garand US .30-06 (7.62×63mm) semi-automatic rifles replaced the earlier bolt-action Springfields, with Thompson M1A1 and M3 "Grease Gun" submachine gun models in US .45 caliber (11.4mm) replacing the older Thompson M1928A1 model. Although the popular Colt pistol was retained, Colt Cobra .38 Special snub-nose revolvers and Smith & Wesson Model 15 revolvers in .38 Special were also adopted. Medium and heavy machine guns, in the form of the M1919A4 US .30-06 Browning (7.62×63mm) – or its M1919A6 light machine gun version – and the larger M2HB .50 Browning (12.7×99mm) were added to the Guardia's arsenal, replacing the ageing M1895 and M1917A1 water-cooled medium machine guns.