Colt Series 70. Sometimes the gun fails to fire and the trigger falls to half-cock.

[Urquhart]

Colt Series 70. Sometimes the gun fails to fire and the trigger falls to half-cock.

The gun has a trigger job and a videcki trigger. Ever since it came back from the smith every 25-50 rounds the gun will fail to fire. I will look at the hammer will not be all the way down.

Could it be the over-travel adjustment? Even though it only does it occasionally?

[hiloboy32531]

Hammer falls to half cock not trigger, might be the over-travel? might be best to send it back to the smith.

[Urquhart]

Yes, sorry, I meant the hammer falls to half-cock.

Does anyone have any suggestions. I will back-out the overtravel adjustment before my next range session. I am just wondering if it might be something else since it doesn't happen but every 25-50 rounds?

[Rich-D]

Back out the trigger set screw in quarter turns. Dry firing it to test for function. Dry firing a 1911 won't hurt it!

Best of Luck!
Rich

[Urquhart]

I can't reproduce the problem during dry fire. It only happens with live ammo.

[Rich-D]

I can't reproduce the problem during dry fire. It only happens with live ammo.

Hmmm! That has me baffled! Hopefully someone will know why it only occurs when firing. Unless the set screw loose and is moving from the effect of recoil.

Best of Luck!
Rich

[niemi24s]

Hi Urquhart:. . .the hammer falls to half-cock.Does the hammer fall to half cock:

A: When the trigger is pulled after the slide fully cocks the hammer and the slide has returned to battery, or...

B: ... as the slide returns to battery after firing a round (aka "hammer follow", or hammer follows the slide but stops at the half cock position) and before the trigger is released and pulled again to fire the next round?

Regards

[Urquhart]

A.


Just every once in a while I will be shooting and the I will hear a click. I look down and notice that the hammer is at half-cock. There is no mark on the primer.

[wichaka]

1/2 cock won't let the hammer strike the firing pin, thus no mark on the primer.

Back out the trigger over travel screw about 1/4-1/2 turn.

[Urquhart]

But 24-49 times out of 50 it works fine. And I can't reproduce it through dry fire. Doesn't that preclude the over-travel screw?

[wichaka]

No, it may be just at the point of the adjustment, where it's not consistent.

[log man]

Wichaka's on it. If when you pull the trigger and you relax immediately, in other words just bump the trigger it can catch. Back it out 1/2 turn. Check is the screw snug?

If you want to see how close it's adjusted, remove the GS and MSH, flip the strut up out of the way and slide the MSH back in to hold the sear spring in place. Now you can pull the trigger back and swing the hammer up and down paying attention to the full cock and half cock locations, you shouldn't feel any rubbing what so ever. If you turn the screw in until you do you will know just exactly how close it's addjusted.

LOG

[niemi24s]

And when you follow Log Man's advice on adjusting the overtravel screw, don't adjust it so the sear just barely misses contacting the half cock notch/shelf. Adjust it so it clears by more than you think it should to compensate for the inconsistencies that Wichaka alluded to.

You don't want to reduce overtravel to zero - that invites the problem you're having and sear nose damage.

You just want to reduce overtravel to an acceptable level - one that lets the gun go Bang every time. The 1911 will resist every attempt to turn it into a Hammerli free pistol! :)

Regards

[Urquhart]

Thanks guys! That makes me feel better. Maybe this will save me the shipping!

[Urquhart]

Dang it! I backed the screw out and it still happens. I backed it out a bunch. Any other ideas?

[ga16de6669]

Well, if the over travel is not giving you the head aches, and the gunsmith is not locally available, theres a plethora of things to check. Is your trigger loose? It may be moving around and not letting the sear do its thing. How does your sear nose look? Is there a break away angle on there? There a possibility the disconnecter is out of speck. It may be rubbing on the slide, or binding, or missing the small radius cut that clears the mag. Were any parts replace during the trigger work or were your existing parts cleaned up? And just to purge any remaining gremlins, are the inner working clean, oiled and not binding. There may be excessive trigger job magic in the workings (steel filings, stone grit ect.) How are all your pins? The hammer pin might be loose and letting the hammer oscillate causing your once a box click.

p.s Is the sear captured by the half cock notch, or is it resting on the shelf?

[Hawkmoon]

The problem began after a so-called gunsmith worked on the pistol, so IMHO the so-called gunsmith should fix it -- on his dime. If the 'smith is local, your next stop should be his place of business.

What else did he do as part of the trigger job? I doubt he just replaced the trigger ... did he replace the sear, tinker with the sear spring, ___?

[Hawkmoon]

If backing out the overtravel screw didn't solve the problem, I would next look carefully at the trigger bow itself. The new trigger could be just a shade longer than the original. Absent an overtravel screw, rearward movement of the trigger stops when the back of the bow hits the arm of the grip safety. It may be necessary to file the arm just a tad ... but only the lower portion, not the upper portion that blocks the trigger when the grip safety is not depressed.

[log man]

+1 with Hawkmoon

With the current information the new trigger bow may indeed be dragging on the under side of the GS arm and occasionally stopping the trigger early. To get a view remove everything from the frame and install only the trigger, (mag catch optional), the sear spring the grip safety and the MSH. In this way you will be able to see the arm interface with the bow and make a determination of where or if and make adjustments as needed.

LOG

[niemi24s]

There's also this from our Tech Issues section which may prove informative: http://www.m1911.org/interact.htm

Regards