Half-Cock Position

[Big Guy]

While shooting yesterday, I noticed the hammer was going into the half-cock position every other stage.

What could cause this? I read somewhere in the forum that this could be caused by a worn out/damaged sear spring. Is this correct?

[Big Guy]

Someone mentioned that adjusting the over-travel screw will take care of this. Any thoughts?

[sperman]

The over travel screw is a good place to start, but it could be a number of things. Try searching the forums for "hammer follow"

[Braxton1]

If you are pressing the trigger and the hammer THEN falls to the half-cock, it's probably a way too tightly adjusted over-travel screw. It's time for a new sear, because the half-cock notch has likely been beating the crap out of the sear nose for some time.

If you are pressing the trigger, the gun fires, and then when you go to press it again, the hammer is already in the half-cock position, that is a different condition known as "hammer follow". I've had hammer hooks wear out, sear noses start to round off, and bad sear springs all cause this.

Unless you're pretty handy around trigger jobs, these will likely be the only tests that you can do in-house:

To check for a properly adjusted over-travel screw,(with an empty gun, of course), cock the hammer. Keep your left thumb on the hammer to control its fall and press-and-hold the trigger. Ease the hammer down. About 3/4 the way down, you should NOT feel a "bump" where the half-cock notch is hitting the sear. If you do, turn the screw out until this goes away and then give it about 1/8 turn more.

This check should be done more-often than most of us do it, particularly with the graphite-shoed triggers or if Loc-Tite wasn't used on the screws in aluminum triggers. They do move. Most of the time, they will loosen excessively but have been known to turn in also.

(Some folks are gonna cringe at this next test. It should only be done ONCE. Done repeatedly, it WILL ruin the trigger job, but should be done once to confirm that the trigger job will hold in the worst case scenario. We run around with loaded guns in holsters and under/over/around obstacles. It had better hold in the worst case scenario...)

To check for proper sear/hammer engagement, lock the slide to the rear. With an empty gun again, trip the slide stop and let the slide slam forward with all its might. Does the hammer follow? If it does, we have a problem. If not, one more test: Lock the slide to the rear again, press and hold the trigger back, then trip the slide stop again, letting it fly forward. The hammer should stay at the full-cock.