Hammer drops to half cock when fired

[skolten]

Using the 1911, after a few rounds the hammer would fall to half cock after squeezing the Trigger, and NO its NOT hammer follow through.The hammer is fully cocked.Sometimes its OK, something is stopping the Sear from rotating away from the half cock notch. The slide is fully closed and it is clean, the over travel screw was backed off to test but still sometimes went to half cock. I suspect something in the disconnector area that its releasing from the sear to soon.. Has anyone had this problem before ?? or can assist me on this...Thank you

 

[jester_s1]

Has the gun been worked on in any way since it last worked right?

 

[skolten]

No its an IPSC gun, it did 2 flawless stages then started this on the 3rd stage.The hammer was cocked ok but fell to half cock when the trigger was pulled.It was stripped and cleaned but still failed a function test. If you keep pulling the hammer back and dry firing the gun, it sometimes drops to half cock but only after the trigger is pulled.This gun has been flawless till now..

 

[skolten]

Found the problem...The trigger bow stirrup was pushing on the disconnector spring allowing the disconnector to drop down, and only just hang on to the sear enough to to release it from the Hammer hooks but not enough to clear the safety notch...

 

[1911Tuner]

skolten nailed it...good show...but if anyone else experiences such a problem...if the trigger has an overtravel screw, that could also be the culprit. Back it out a half-turn and see if the problem goes away. If it doesn't, apply a little more tension to the center leg of the sear spring to keep the disconnect from dropping off the sear. There's also a chance that the trigger stirrup is pushing the sear spring off the disconnect, which is unlikely if the trigger has an overtravel screw, but possible is it doesn't have the screw and the grip safety's overtravel stop surface is out of spec.

 

[skolten]

Thanks 1911 Tuner, is was actually your previous post a while back, that steered me in the right direction, it was the only thing I had not looked at. I had checked the over travel adjuster but it made no difference no matter what I did, I generally set it so with the trigger squeezed ,rotating the hammer there is no dragging past the safety notch and hammer hooks. The disconnetor paddle and rear angle did not look to good so I replaced that, and tweeked the spring, checked the disconnect - lower sear leg clearance with the slide back a bit and all is sweet, just need to test fire it. It was that bad with the grip safety removed, mainspring housing in, hammer cocked, I jiggled the trigger and could see the disconnector slowly drop down, squeezed the trigger and the hammer dropped to half cock..Thanks ...Skolten