The Luger uses a toggle-lock action, which uses a jointed arm to lock, as opposed to the slide actions of almost every other semi-automatic pistol. After a round is fired, the barrel and toggle assembly (both locked together at this point) travel rearward due to recoil. After moving roughly one-half inch (13 mm) rearward, the toggle strikes a cam built into the frame, causing the knee joint to hinge and the toggle and breech assembly to unlock. At this point the barrel stops its rearward movement (it impacts the frame), but the toggle and breech assembly continue moving (bending the knee joint) due to momentum, extracting the spent casing from the chamber and ejecting it. The toggle and breech assembly subsequently travel forward (under spring tension) and the next round from the magazine is loaded into the chamber. The entire sequence occurs in a fraction of a second. This mechanism worked well for higher pressure cartridges, but cartridges loaded to a lower pressure could cause the pistol to malfunction because they did not generate enough recoil to work the action fully. This resulted in either the breechblock not clearing the top cartridge of the magazine, or becoming jammed open on the cartridge's base.
In World War I, as submachine guns were found to be effective in trench warfare, experiments with converting various types of pistols to machine pistols (Reihenfeuerpistolen, literally "row-fire pistols" or "consecutive fire pistols") were conducted. Among those the Luger pistol (German Army designation Pistole 08) was examined; however, unlike the Mauser C96, which was converted in great numbers to Reihenfeuerpistolen, the Luger proved to have an excessive rate of fire in full-automatic mode.
The Luger pistol was manufactured to exacting standards and has a long service life. William "Bill" Ruger praised the Luger's 55 degree grip angle and duplicated it in his .22 LR pistol.