“John Moses Browning invented the Army’s more potent sidearm 103 years ago! It replaced the anemic Colt Single Action Army (SAA) that was chambered in .38 Colt”
The Colt SAA was a .45 cal, the Colt New Service was a .38.
The SAA was chambered in many rounds, .45, .44 Special (rare), .44-40, .41 Colt, .38-40, .38 Special, .32-20, .25-20, and later .357 Mag.