The Obregón is a Mexican

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 designed semi-automatic pistol

Pistol

When distinguished as a subset of handguns, a pistol is a handgun with a chamber that is integral with the barrel, as opposed to a revolver, wherein the chamber is separate from the barrel as a revolving cylinder. Typically, pistols have an effective range of about 100 feet.-History:The pistol...

 designed in the mid-1930s by a mechanical engineer, Alejandro Obregón. It uses the same .45 caliber ammunition as the Colt 1911 and resembles it in overall appearance, frame size and weight. However, its short-recoil operating and barrel locking system employs a diagonal cam on the rear of the barrel sliding against a diagonal receiver-mounted groove to rotate the barrel, much like that of the Austro-Hungarian Steyr M1912

Steyr M1912

The Steyr M1912 was developed in 1911 by the Austrian firm Steyr Mannlicher by Karl Krnka, based on the basic operating system of the Roth-Steyr M1907. It was developed for the Austro-Hungarian Army and adopted in 1912 as the M1912...

 pistol, not the "swinging link and pin" of the Colt M1911 series.

One of the Obregón's design curiosities is that its safety switch and slide lock are a single unit. A few hundred of these pistols were produced at the national armory in Mexico City

Mexico City

Mexico City is the Federal District , capital of Mexico and seat of the federal powers of the Mexican Union. It is a federal entity within Mexico which is not part of any one of the 31 Mexican states but belongs to the federation as a whole...

during the 1930s, but it was neither a sales success nor was it commissioned to be made for the Mexican government.