A properly shaped and tuned extractor is crucial to reliability in the 1911 pistol. Most factory extractors and many aftermarket extractors need attention to achieve the optimum in reliability
The first area of attention is the extractor groove itself, where the rim of the cartridge rides up into the groove from below. The extractor, when properly fit, does not "snap" over the rim of the cartridge, but the cartridge pushes up from below as it is fed from the magazine. One of the surest ways to ruin an extractor is put a round directly into the chamber, and then drop the slide. This forces the extractor to snap over the rim, and in time will ruin the extractor’s shape or break it.
The extraction groove must be beveled at the bottom of the groove so that the rim of the cartridge is cammed gradually into the groove. In this way, the cartridge rim will more gradually push the extractor back to tension it over the extractor groove in the cartridge and it can slide up more easily. This bevel should run from the bottom edge of the extractor groove up to the midway point in the extractor’s groove. The forward inside edge of the extractor groove should be beveled out to form a slight angle; since the cartridge is at an upward angle when it feeds, this allows the rim to slide into the groove at the proper angle. The angle of the majority of the inside extractor claw should not be altered by filing or polishing. It should remain at 90 degrees or even have a slight inward grasp. The lower edge of the extractor claw should be beveled and rounded; the forward outside edge should be rounded. The top and bottom rear edges of the body of the extractor should be beveled for about an inch and ½ so as to allow "wiggle room" for the extractor within its hole in the slide. Then the tip of the extractor and the inside of the extractor groove should be polished. The initial shaping is done by small files; the polishing is done with fine sandpaper and Flitz.
Proper tensioning of the extractor is vital to reliability. Too much tension and chambering will be severely impeded or prevented. Too little tension, and extraction and ejection will be weak or non-existent. An old gunsmith trick to test the tension of the extractor is to remove the slide from the pistol, and push a round of ammo up under the extractor from below. With proper tension, the round should be held in place regardless of how the slide is turned, yet when the round is moved downwards from its center position about 1/10 of an inch, the round should drop off.
Tension is adjusted by removing the extractor, reversing it in the extractor hole in the slide, and pressing sideways one way or the other to increase or decrease tension. The depth of the extractor’s protrusion into the case area is controlled by removing a slight amount of metal from the inside of the rounded protrusion just back of the extractor claw with a file.