Comparing the 1911 and 1911A1 side by side (VIDEO)

With John Moses Browning’s USGI .45 longslide reigning strong for well over a century, Hickok45 has the lowdown on what the differences are that sets the A1 apart from its older brother.

With experience earned in the U.S. involvement in the Great War (and feedback from other countries that adopted the pistol) the M1911A1 Government model was revamped around 1924 which included a number of little tweaks aimed to make it more controllable and less prone to hammer bite. These mods included a shorter trigger, some minor cutouts in the frame, an arched mainspring housing, a longer grip safety spur and modified grips.

Of course, Hickok explains it much better.