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Need help with 1911- half cock failure

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Nothin worse than goin off half cocked.
I have a 1911 made in 1918. I received this from CMP and now learning about what parts were swtched out etc. It passed all the std function tests except...the hammer will drop from 1/2 cock position when the trigger is pulled. Not suposed to do that...right? Could use some advise from you knowledgeable fellow members. Thanks
 
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Andy54Hawken

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Worn half cock notch on the hammer...?
Maybe debris on the hammer...causing this...?

Not sure where one can get a proper 1911 hammer...maybe Brownell's...
Andy
 
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According to The Colt .45 Automatic A Shop Manual by Jerry Kuhnhausen, drops from 1/4 cock means the hammer 1/4 cock ledge is broken or altered. Fix is replacement of the hammer. If you have a choice you should get the correct style replacement hammer for your pistol 1911 Hammers
If you contact the CMP they will probably send you a replacement hammer. They have excellent customer service.[/i]
 
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I do not have a govt issues 1911 but I do have a Remington R1 which is supposed to be close in most respects. My 1/4 stop also drops when the trigger is pulled and does so correctly according to Remington. 1/4 stop is not a safety for anything but a slip of the thumb when manual cocking.
Could yours function the same?
 
I do not have a govt issues 1911 but I do have a Remington R1 which is supposed to be close in most respects. My 1/4 stop also drops when the trigger is pulled and does so correctly according to Remington. 1/4 stop is not a safety for anything but a slip of the thumb when manual cocking.
Could yours function the same?
I have a Remington 1911R1 too as well as several USGI M1911s and M1911A1s. The Remington 1911R1 has a Series 80 type hammer and the hammer dropping from 1/4 cock when the trigger is pulled is normal behavior. That is also confirmed by the book I referenced above. I just went out to my safe and verified that my Remington 1911R1 hammer drops from 1/4 cock when I pull the trigger but my USGI pistols do not.
 
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F
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Thanks gents ... Guess I'll take it apart to figure it out. This 1911 has the original long trigger in it...not sure that matters. I also have a 1943 1911A1 and the 1/2 cock will not drop on trigger pull. Stay tuned.
I should not quess about safety but it should be safe to shoot? I never use 1/2 cock on a semi pistol anyway.
 

KKG

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I want to the U.S. Army Small Arms Repairman School in Aberdeen Proving, Maryland. And some other classes. I NEVER heard of a 1/4 cock notch on any 1911A1 design. Including the one used by the fine folks at Detonics .45 Associates - I was one of those fine folks.

The 1/2 Cock Notch was designed by Mr. Browning as a Safety should the Gun accidentally slip off Full Cock.

flashpan; You Pistol is NOT safe the way it is.
 

jbett98

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My guess is that the trigger might somehow be preventing the sear from fully engaging the half cock.
That's from my experience with 70 series National Match Gold Cups that had the trigger over travel screw adjusted wrong.
Is there free play between the trigger and the sear/disconnector?
 
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I want to the U.S. Army Small Arms Repairman School in Aberdeen Proving, Maryland. And some other classes. I NEVER heard of a 1/4 cock notch on any 1911A1 design.
We're talking abut the same notch. The Kuhnhausen books (two volumes), which many consider to be the bibles of 1911 gunsmithing, refer to it as the 1/4 cock ledge. And when you actually cock the hammer you see that it actually does stop closer to 1/4 cock than 1/2 cock. But whatever you choose to call it it is the same ledge on the hammer.
 

KKG

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We're talking abut the same notch. The Kuhnhausen books (two volumes), which many consider to be the bibles of 1911 gunsmithing, refer to it as the 1/4 cock ledge. And when you actually cock the hammer you see that it actually does stop closer to 1/4 cock than 1/2 cock. But whatever you choose to call it it is the same ledge on the hammer.
Personally, I've never seen a need for looking at those Books. I've been lucky enough to see the Original JMB Patient Papers. The Notch is shown on them as a 1/2 Cock Notch.
 
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If the sear is at the 1/2 - 1/4 cock notch on the hammer, yes it is normal for the hammer to fall the rest of the way when the trigger is pulled...as the 1/2-1/4 notch is not captured as later and other models may have.
 

KKG

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If the sear is at the 1/2 - 1/4 cock notch on the hammer, yes it is normal for the hammer to fall the rest of the way when the trigger is pulled...as the 1/2-1/4 notch is not captured as later and other models may have.
This isn't true for a 1911A1 of it's in the right state of repair. If this Notch is probably shaped as called for in the Original Design it very deep and actually acts to trap the Sear.
 
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This isn't true for a 1911A1 of it's in the right state of repair. If this Notch is probably shaped as called for in the Original Design it very deep and actually acts to trap the Sear.
As was originally posted, it's a 1918 vintage which is not an A1 model.

And as I mentioned; "...captured...as later and other models may have."

Have seen quite a few hammers that will not capture the sear. Not a big deal, as the hammer is too close to the pin to provide any force to fire it.
 

Ura-Ki

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It's my understanding that the 1/2 notch was to allow carry with a loaded chamber with the hammer at half cocked so as not to have it resting on the firing pin and putting pressure on a primer! None of mine have this, it's ether cocked all the way, or like a series 80, resting at a 1/4 UN COCKED position that cannot fall the rest of the way no matter what! Even my Series 70's have this set up!
 
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Hammer from a Colt Officers Model Series 80. Note the notch will not capture the sear at 1/2 cock.

Not capturing...means one can actuate the trigger and the sear will release from the notch without first having to pull the hammer back a bit.

20190817_155025.jpg
 
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Hammer from a Colt Officers Model Series 80. Note the notch will not capture the sear at 1/2 cock.

View attachment 609278
I want to the U.S. Army Small Arms Repairman School in Aberdeen Proving, Maryland. And some other classes. I NEVER heard of a 1/4 cock notch on any 1911A1 design. Including the one used by the fine folks at Detonics .45 Associates - I was one of those fine folks.

The 1/2 Cock Notch was designed by Mr. Browning as a Safety should the Gun accidentally slip off Full Cock.

flashpan; You Pistol is NOT safe the way it is.

I was trained by Richard Neimer, who was a gunsmith at Detonics in the 80s until they closed in Seattle.

Yes, all Detonics 1911 style pistols have a 1/2 cock notch.

Most are captured, some are not. As long as the sear is tensioned correctly by the sear spring, it will catch that notch and keep the hammer from contacting the firing pin.
 

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