Most semi-automatic pistols operate by means of recoil.
Smith & Wesson semi-automatic handguns, such as the popular Sigma series of pistols, operate using the principle of recoil. The force generated against the bolt face by the discharge of a cartridge, or recoil, drives the bolt and slide assembly back to open the chamber and eject the spent round. The rearward movement of the slide compresses a powerful recoil spring, which expands to draw the slide and bolt forward to chamber a new round of ammunition. A weakened or damaged recoil spring can cause a failure to feed, and should be replaced as soon as the problem is detected.
Instructions
1. Press the magazine catch on the left side of the pistol grip and remove the magazine from the weapon. Pull back the slide to eject any chambered cartridge, then inspect the chamber to ensure the weapon is unloaded.
2. Depress the slide stop on the left side of the frame and release the slide to close the action. Pull the trigger once to release tension on the hammer spring, then remove your finger from the trigger guard.
3. Grasp the back of the slide, then move the slide 1/8 inch to the rear. Push in the take-down catch with the thumb and forefinger of your free hand. The take-down catch protrudes from both sides of the frame, just above the trigger guard.
4. Hold in the take-down catch, then push the slide forward and off the frame of the pistol. Keep a firm grip on the slide so the recoil spring and guide assembly don't come flying loose.
5. Turn the slide over so its bottom faces up. Grab the recoil spring and guide assembly, then push it slightly forward to disengage it from the barrel lug. Pull the assembly back and out of the frame. The front of the recoil spring fits into a hollow housing at the front of the slide; be careful not to twist or bend the spring while removing the assembly.
6. Slide the recoil spring forward and off the guide, then set it aside. Slide the replacement recoil spring onto the front of the guide rod, then back along the guide rod until it seats against the guide stop.
7. Press the front of the recoil spring and guide assembly back into the housing at the front of the slide. Make sure the spring seats firmly against the front of the housing. Slightly compress the spring, then push the guide stop into place against the barrel lug.
8. Push the slide over the guide rails on the frame, then toward the rear of the pistol until the take-down catch engages to lock the slide in place.
Tags: recoil spring, take-down catch, assembly back, guide assembly, recoil spring guide, spring guide