The Colt M1911A1 pistol is a single action, semi-automatic sidearm used by the Tau'ri.
Lt. Hammond carried a M1911A1 as a sidearm when he encountered SG-1 in 1969. (SG1: "1969") Since the Atlantis expedition's second year of operation, Lt. Col. John Sheppard has replaced the standard M9 Beretta pistol with an M1911A1 as his preferred sidearm, possibly due to its greater stopping power. The custom model Sheppard carries appears to have adjustable sights fitted. The particular variant he uses is the Para Ordnance P14 high-capacity .45 ACP. (SGA: "Instinct", "Irresponsible")
- In an alternate reality, LVPD Detective Sheppard carried a bright chrome or stainless steel model of the M1911A1 with pearl grips and fixed sights. (SGA: "Vegas")
- The 1911 style pistol is heavily favored by all kinds of special operations forces, civilian and military, in the United States. The FBI Hostage Rescue Team, LAPD SWAT, Marine Force Recon, and 1st Special Forces Operational Detachment—Delta (Delta Force) are all known users of the type. Though no US military unit is known to use the Para-Ord hi-cap variant, it is hardly outside the realm of probability that a ranking officer in such a highly specialized command could get one if he so desired.
- Sheppard's selection of this weapon shows considerable savvy in choice of sidearm, as well as more advanced pistol training than the common run. The single-action mechanism of the 1911 style demands a higher standard of handling and execution than the M9's double-action operation. With the advent of double-action 9mm pistols as the standard sidearms for most world militaries, the 1911 is regarded more and more as a "specialist" or "professional's" weapon, now seen mostly in the hands of those considered "elite" operators.
- Sheppard's choice of the 1911 style works to his advantage on at least one occasion when he beats Acastus Kolya (and his double-action automatic) to the draw in "Irresponsible".
- Using this weapon Sheppard notably kills the Wraith Commander from "Aurora", Acastus Kolya in "Irresponsible" and Queen Coldamber in "Submersion".