The 1960s were boom years for Colt with the escalation of the Vietnam War, Robert McNamara shutting down the Springfield Armory, and the U.S. Army's subsequent adoption of the M16, for which Colt held the production rights and would sell over 5 million units worldwide. Colt would capitalize on this with a range of AR-15 derivative carbines. They developed AR-15-based Squad Automatic Weapons, and the Colt SCAMP, an early PDW design. The Colt XM148 grenade launcher was created by Colt's design project engineer, gun designer Karl R. Lewis. The May 1967 "Colt's Ink" newsletter announced that he had won a national competition for his selection and treatment of materials in the design. The newsletter stated in part "In only 47 days, he wrote the specifications, designed the launcher, drew all the original prints, and had a working model built". At the end of the 1970s, there was a program run by the Air Force to replace the M1911A1. The Beretta 92S won, but this was contested by the Army. The Army ran their own trials, leading eventually to the Beretta 92F being selected as the M9.