Overtravel adjustment and half-cock ?

[Zak Smith]

I have a question about the interaction between half-cock and the overtravel adjustment on my trigger. The pistol in question is a CZ-75SA, but the principles should be the same for any pistol that has a half-cock notch and an overtravel screw.

Tightening in the overtravel screw on the trigger limits the distance the trigger travels to the rear after the sear releases, and so limits the upward movement of the sear. If the overtravel screw is in too far, the sear will not be able to move up enough, and it won't even release the hammer.

On my CZ's that have the overrtavel ajustment, if I set up the screw by screwing it in until the hammer won't fall, and then back out about 1/2 turn, I get a great trigger pull. However, if I dry-fire and keep the trigger pulled in, and then move the hammer back and forth with my fingers, I can feel resistance as the half-cock notch passes under the sear. This happens because there is so little clearance between the sear and the hammer notches with the screw in so far.

If I turn the screw out another couple turns, there is no resistance.

I know that having the screw in far can lead to light hammer strikes due to sear/hammer friction.

My question is: Should I worry about wear on the sear due to the resistance of the half-cock notch?

Thanks
Zak

 

[bountyhunter]

"My question is: Should I worry about wear on the sear due to the resistance of the half-cock notch?"

YES. The half cock notch is frequently taller (sticks out more) than the full cock notch to ensure it will catch the sear on an accidental fall. If you pull the trigger fully and can still feel the sear face dragging on the half cock notch as it goes by, it's too close. The hammer will fall and the gun may fire, but it chews off the front edge of the sear. An overtravel screw has to be out far enough that the sear will clear the hammer cleanly when pulled.