Hammer falls when trigger is pulled at half cock

[Ric4509]

I just noticed that my Dan Wesson Dave Pruitt's hammer will fall when the trigger is pulled at half cock. I bought a Wilson's ultralight hammer and A-2 sear, installed the set and the same thing happens. Then I replaced the original set 2x with Chip McCormick hammers and sears in my 1911 parts box and the hammer still falls when the trigger is pulled at half cock. I've installed Colt sears and the same effect. Now I'm thinking of replacing the original hammer and sear with either a Nowlin Action Kit or Cylinder and Slide's trigger pull set kit. What I suspect is that the hammer and sear pin holes in the frame are not mil spec. Has anyone experienced this problem? Would appreciate an advice, thanks.

[Pappy]

Hi Ric. There are extended pins that can be installed on the frame to allow you to mount the sear etc. on the outside of the frame. Then you can see the relationship of parts very easily... This might help you...Pappy

[Hawkmoon]

If these are Series 80 style parts, this doesn't indicate a problem. The half-cock position on a Series 80 hammer doesn't have a lip to retain the sear. The series 70 (and older) hammers have a lip, which is why on those it is referred to as a half-cock "notch." The series 80 hammer doesn't have a "notch," only a flat detent.

[Hunter]

On my Colt series 80 1911s the hammer will fall from half cock when the trigger is squeezed. The series 70 will not. Depending on your set up that could be normal I believe.

[John]

What Hawkmoon says, normal for a particular style of hammers.

[Ric4509]

Pappy = thanks, good point. I forgot about those extended pins.
Hawkmoon = yup, I'm familiar with the series 80 hammer, thanks.
Hunter = I did the pencil test and the pencil came out the barrel flying when I pulled the trigger at half cock.

Thanks guys I'll let everyone know what the fix is.

[Ric4509]

The same thing with my Dan Wesson Commander Bobtail.

[3006mv]

I am being redundant but yes the Chip McCormick hammer is a series 80 and will drop on a series 70 frame.

[Ric4509]

What I didn't realize is that when I changed the trigger that's when the hammer drops at half cock when the trigger is pulled. I replaced the trigger with the original and the problem is solved.

1911tuner, Hawkmoon, Pappy, Wichaka - Is it because of the trigger bow thickness that in a way pushes the sear inwards?

[John]

You mean that with your previous trigger the hammer does not fall from the half-cock notch, when the trigger is pulled, but it falls with the new one? Then most probably your new trigger's bow is too long, and does not allow the sear to fully go inside the hammer's half-cock notch.

[Ric4509]

John - I guess that's what it is. I replaced the original w/c I believe is a Chip McCormick aluminum trigger like the old polymer/plastic Kimber trigger. I installed a Greider match trigger, Wilson Combat trigger, Videki trigger, replaced the sear with all the sears (4) I can find in my 1911 parts box and the hammer falls in half cock mode when trigger is pulled. Learned something new, again!

[John]

And the hammer has a captive half-cock notch?

[ewtcoma]

Hello,

I seem to be having a similar problem but it may not be a problem at all but just the way the 1911 works. I seem to have the same issue with all 3 of my 1911s, One kimber CDP and 2 springfeilds, a TRP and a milspec. They each have thousands of rounds through them.

I have worked on them but never done anything realy drastic except to change out the springs to wolf.

I seem to be experinencing the same situation with hammer follow but It does not seem to be that big of a problem. I had never had a issue on the range but when I was doing a function test I discoverd it.

I explain the situation here.

1. if I hold the trigger all the way back and rack the slide then the hammer does stay locked back.

2. If I hold the trigger half way or sloppely grasp the trigger with a strong grip it then gets hammer follow. Now it does not hit the firing pin but it does drop down to the half cock notch. Does this seem like that this is a problem?

[John]

Somehow I do not think these are neither safe ways to handle the pistol, nor the proper tests.

The original test was for the hammer falling from half-cock. In other words, cock the hammer enough to reach the half-cock notch. Pull the trigger. Does the hammer falls?

You are discussing hammer follow up, which can be a related issue, but it is not tested as you describe it.

First test is to lock the slide back and release it using the slide stop. This is not something that you should do very often, since it can destroy the trigger job of the pistol. Did the hammer followed down to the half cock notch? If so, try putting some more pressure on the middle leaf of the sear spring.

You never test the pistol holding the trigger half-way. The trigger is either held all the way to the rear, or is left all the way forward.

[TomN]

John & All,
Several years ago, I bought a Combat Commander project that the builder was not able to finish. I assembled the gun adding a few "better" parts and replacing some parts that had gotten lost when it was apart. The gun now has a 4.5 pound trigger, cycles well, handles well and shoots well. I really like the gun and it is unusual as it has a "squared off trigger guard" and other modifications.

The problem is that the hammer will follow the slide when the slide is released from the reward position to chamber a round. Another pieces of data, if you hold pressure on the trigger when you release the slide lock, the hammer does not follow the slide. Also if you do not have the grip safety "engaged" (pushed in) the hammer stays back.

The gun has been fitted with a Gold Cup trigger, Chip McCormic hammer, sear, sear spring. It also has an extended safety and slide stop.

After I read the above thread, I changed the sear spring back to the original and after that did not fix it, I "adjusted" the spring to apply more pressure onto the sear. Still did not fix the hammer follow.

I have a second Commander which functions fine. In the past, I have swapped out all the parts (sear, sear spring, hammer, disconnector, grip safety...) and to my suprise the second gun still functions correctly but the original pistol will still allow the hammer to follow the slide.

Really frustrating........any help would be appreciated.

Thanks, Tom

[John]

The fact that the hammer does not follow when the slide is released but the grip safety is engaged, means (to me at least, and I am nowhere near being a gunsmith) that your problem is due to bouncing trigger. Let me try and explain my reasoning (so that more experienced members can tell me, if I am right or wrong here).

When the grip safety is not depressed, its tongue is touching your trigger, thus it does not allow it to move back at all. When the grip safety is depressed, the trigger can move backwards. Since the hammer follows when the slide is released with the grip safety is pressed, but does not follow when the grip safety is not pressed, it means that your trigger moves backward, when releasing the slide with the grip safety pressed. So far so good, now the reason why the hammer follows?

I would suspect an improper sear/disconnector fit, which was the byproduct of a hairy trigger job. I suspect that your sear does not fully engage the hammer hook, thus the slightest trigger movement allows it to break from the hammer and let it fall to half cock. We have established that when you do not press the grip safety, that does not happen, because the trigger does not move. Also, when you are holding the trigger back, the hammer does not follow, because now the disconnector is not between the trigger and the sear, so the sear does not move.

I would let others suggest fixes for this issue, maybe some trimming of the sear legs would help, but my guess is that you need a set of drop-in hammer/sear/disco. Check the ones available in Cylinder & Slide web site. But do not do anything, unless you hear from 1911Tuner or another one of our most gunsmithing-oriented members.

[ewtcoma]

Hey,

Readjusting the sear spring to the original tension had fixed the problem. I was thinking that was the problem because I did try to lighten it up but went to far. Thats what I get for playing shade tree gunsmith.