1911 half cock problem; assistance please.

[Sky]

My ACll 1911 was on a computer printer and some how it fell to a tiled floor landing directly on the hammer. Put a chip in the floor but absolutely no visible damage to the pistol. I think the pistol was at half cock when it fell but am not sure.....

Of course I did a function check and even shot a couple of mags through the weapon. The Crimson Trace was even still zeroed!!

But here is the problem: at half cock with firm trigger pull the hammer will now fall. I have not taken the grip off or really explored what part or parts I might need to order simply because of other chores but figured I might ask some of our members what they think before I really get involved with the fix...Thanks

M1911A1 Steve wrote:

The 1911 has a hammer notch that is not its cock notch, it's true. But it's not a half-cock notch, either.
It's there to catch the hammer in mid-fall, if somehow it should become dislodged from its cock notch, so it doesn't fall on the firing pin and ignite a cartridge accidentally.
As you probably know, it is safe to carry a 1911 in Condition Two because the firing pin will not contact a cartridge's primer unless it has first been given a strong blow by the pistol's hammer. The Army thought that Condition Two was safer than Condition One, on horseback.
Cavalrymen were instructed to cock the pistol while it was still in its holster, and only then to make a presentation. The "half-cock" notch was there to catch the hammer, should the trooper's thumb slip.
The "half-cock" notch is neither strong enough nor deep enough to act as a safety device of the sort seen on the hammer of a Single Action Army revolver. It should never be used as a half-cock-safety notch.

http://coolgunsite.com/funcheck/function.htm

HALF-COCK TEST: Using thumb, pull hammer back until the first audible click. Hammer should be at half-cock notch. Grip gun normally, attempt to pull trigger. Hammer should NOT fall for any reason, unless the gun is a Series 80 commercial. These guns have a re-designed half-cock notch that engages near the at-rest position, thus the hammer cannot fall hard enough to strike the firing pin with force. MILITARY GUNS WILL ALWAYS USE THE OLDER HALF-COCK NOTCH, WHICH SHOULD NEVER ALLOW THE HAMMER TO FALL.

I actually hope something got bent internally and the old mallet can be brought into service.

http://search.yahoo.com/r/_ylt=A0oG...yusa.com/General.mvc/Index/Schematics~Gov1911

 

[Andrew Wyatt]

you need a new hammer and possibly a new sear.

 

[David E]

Is it 1/2 cock or 1/4 cock?

If 1/4, it's supposed to release the hammer with a firm pull.

If 1/2, then something needs to break or already be broken for the hammer to fall.

If the hammer was resting at either 1/4 or 1/2 cock, then it's likely the hammer and/or sear was damaged by that fall.

Had the hammer been fully forward, it wouldn't be a problem.

 

[Sky]

Is it 1/2 cock or 1/4 cock?

1/8 or 1/4 not half cock..first click when hammer pulled back; only has 2 clicks 1/4 and full cock. I probably sheared the first detent off the hammer during the drop...dumb, dumb, dumb.

 

[cyclopsshooter]

Do you know how to detail strip the receiver? Pics of small parts like hammer and sear would be useful.

 

[Greg528iT]

If 1/4, it's supposed to release the hammer with a firm pull.

HUH????????????

There should only be 2 positions in which the hammer engages the sear. Full cock and Half cock. Now half cock might be more than halfway around, but don't let the semantics get in the way.

It sounds like the hammer broke the half cock land. The only way to know is to fully strip it and inspect it. Chances are if it hit hard enough to break the hammer the sear is not going to be in great shape.

Here is a picture of 2 hammers at the extremes of design. Wilson hammers for example will capture the sear, but not nearly to the extent of the original design.


New hammer and sears can be had at reasonable prices. Some claim to be drop in, but they are for sure, FULL inspection. IE.. I dropped in a set but did do checking of angles, engagement etc etc..

 

[1911Tuner]

If the hammer has a flat quarter-cock shelf, it will fall from that position when the trigger is pulled. If it has a captive half-cock notch, it won't...or at least it shouldn't. I'm not familiar enough with the American Classic pistols to make a call on which type of hammer it has.

 

[Sky]

Hey guys great replies and it is appreciated. I can take anything apart ( putting it back together can be tedious at times) I will get my nerve up later and see how the hammer notch or land looks and go from there....Again thanks.

 

[1911Tuner]

I guess the best clue is to pull the trigger and see if it feels smooth or rough. Steel never breaks cleanly on impact. If you broke something, you could feel it.

Does the ACII have a passive firing pin safety?

 

[David E]

1/8 or 1/4 not half cock..first click when hammer pulled back; only has 2 clicks 1/4 and full cock. I probably sheared the first detent off the hammer during the drop...dumb, dumb, dumb.

No, you probably damaged the sear, not the hammer.

From 1/4 (or 1/8th cock) the hammer will fall when the trigger is pulled, which it does. As a result, we can't tell without pics or personal inspection if any real damage occurred.

 

[David E]

HUH????????????

There should only be 2 positions in which the hammer engages the sear. Full cock and Half cock. Now half cock might be more than halfway around, but don't let the semantics get in the way.

It's not semantics, it's what it is. Colt introduced the "1/4 cock" notch/stop in the Series 80. It is different than the traditional 1/2 cock notch, both in design and function, but the intent is the same: to catch a falling hammer that was released inadvertently. 1/2 cock is not a safety, per se, but a safety feature.

It sounds like the hammer broke the half cock land.

No, we can't tell from his description if any damage occurred.

 

[Greg528iT]

Colt introduced the "1/4 cock" notch/stop in the Series 80.

but the intent is the same: to catch a falling hammer that was released inadvertently

Maybe I'm learning something. I have in the last 2 years of reading this forum, never heard anyone use the term 1/4 cock. Since as you say the intent is the same, it probably is called 1/2 cock by everyone else. Sounds the picture to the right in my previous post, a land to catch the sear.

1/2 cock is not a safety,

Don't let Tuner hear you say that. He'll quote the original JMB design as a safety.

 

[David E]

Maybe I'm learning something.

It happens sometimes!

I have in the last 2 years of reading this forum, never heard anyone use the term 1/4 cock. Since as you say the intent is the same, it probably is called 1/2 cock by everyone else.

But they are different. 1/2 cock is located about 1/2 way up the arc of travel. When the sear is in the 1/2 cock notch, a hard trigger pull will not dislodge it.

The 1/4 cock stop/shelf is located much closer to the fully forward position, just slightly off the firing pin. When the sear engages this stop, a pull of the trigger will release the hammer, as this design intends.

If a hammer dislodges from the 1/2 cock position, the hammer can generate enough momentum to fire a chambered round. The same hammer falling from 1/4 cock cannot.

Don't let Tuner hear you say that. He'll quote the original JMB design as a safety.

Tuner would be right on that, but there is original design on paper and there is what's proven to work best in actual use. The aforementioned ability of a dislodged hammer to discharge a round from 1/2 cock being one of them. That would typically require something to be broken, but not always. It's impossible to chamber a round without the hammer being fully cocked. One needs to manually lower the hammer to 1/2 cock, per the protocol at the time. What happened now and then was that edge of the sear would rest the edge of the 1/2 cock notch, outside the notch proper. Two aligned knife edges under tension doesn't take much to dislodge, even if the trigger is never touched. (some rode horses, remember) This could result in an AD.

Hammer fully forward is still much safer than carrying a chambered 1911 on 1/2 cock, just as it was much safer in 1911, regardless of what JMB's original design or intent called for.

 

[1911Tuner]

Don't let Tuner hear you say that. He'll quote the original JMB design as a safety.

It is a safety, as was the captive half-cock on all of Browning's exposed hammer guns. The Models 92 and 94 Winchester rifles, and Model 97 shogun are examples.

If a hammer dislodges from the 1/2 cock position, the hammer can generate enough momentum to fire a chambered round.

How is it going to dislodge? It captures and interlocks the sear with the hammer. The sear can't move in either direction. The only way to dislodge it is to finish cocking the hammer.

What happened now and then was that edge of the sear would rest the edge of the 1/2 cock notch, outside the notch proper.

There are a lot of "what ifs" in that one. If the failure of the sear to reset keeps it from entering the half-cock notch, it's not likely that it would reset and hold full cock either.

This is a little like the belief that a 1911 can blow up if it fires out of battery. Unless there's a serious issue with the upper lug engagement depth, it can't fire far enough out of battery to blow it up. It's mechanically impossible.

 

[Sky]

I always heard the position of the hammer at first click was referred to as half cock; also always heard there were UFOs but alas I have not seen one. The ACll is like a 70 series without the extra 80 series safeties.

As in my first post it was my understanding the whole purpose was to prevent a ND when the hammer was being cocked by thumb and the thumb slipped before full cock.

Now: when I pull the trigger from "half cock" it takes a lot of "pull" but the hammer will fall, crisp, no grit, just snaps and falls.

When I get around to taking the pistol frame innards apart I will post and let you guys know what I find. I am not a 1911 guru by any means just an end user who has used them off and on for a life time; first firearm I ever had drop on a tile floor and I wasn't even there when it happened?? Think the printer went through a diagnostic and the slight vibration (?) was just enough to cause the pistol to slide off the angled smooth surface??..

Tear down is not a high priority for me in that I have a few other pistols I use for night stand duty; just bugs me even though the pistol seems to shoot just fine.

I will tear it down just do not know when; my wife has me tied up doing couple stuff with friends, family, and people I don't even know! Not a good time for me to start.

 

[David E]

It is a safety...

I'll go down this rabbit trail once with you....

I agreed it was designed as a "safety."

How is it going to dislodge? It captures and interlocks the sear with the hammer. The sear can't move in either direction. The only way to dislodge it is to finish cocking the hammer.

Did you miss the part where I said "typically, that requires something to be broken?" In the cavalry, the SAA was discharged more than once when a trooper threw the stirrup down, hitting the hammer, shearing the "safety notch" and firing. A blow to the 1911 hammer at 1/2 cock would do the same thing.

There are a lot of "what ifs" in that one. If the failure of the sear to reset keeps it from entering the half-cock notch, it's not likely that it would reset and hold full cock either.

That's not at all what I said. I said its possible to lower the hammer so the edge of the sear rests on the outside edge of the 1/2 cock notch. I said nothing at all about the sear being unable to enter the notch, or anything at all being amiss. In fact, I used the example to show how a perfectly sound 1911 can discharge from 1/2 cock. Now, this does require the person to improperly keep pressure on the trigger as the hammer is lowered to get the sear in that position. With the sear resting on the 1/2 cock edge, the travel arc is even greater than when 1/2 cock is properly engaged.

Go ahead and try it, as it sounds like you've never done so. It's surprisingly easy to do. Nothing "mechanically impossible" about it at all.

 

[David E]

Now: when I pull the trigger from "half cock" it takes a lot of "pull" but the hammer will fall, crisp, no grit, just snaps and falls.

If the hammer is dislodging from a true 1/2 cock position with a trigger pull, it's broken.

The 1/4 cock stop doesn't require a hard pull to dislodge.

I'm curious why a 1911 is lying around the house on 1/2 cock.......was the chamber loaded?

 

[MTO]

For what it's worth, this thread interested me, and I would like to provide results from a test I just did:

I just tried S&W, Dan Wesson, and Springfield 1911s and a Springfield EMP.

The following all have half-cocked positions that can be reached either by thumbing the hammer back or by pulling the trigger from full-cocked, releasing the trigger, and easing the hammer down:

S&W 1911
Dan Wesson 1911
Springfield EMP

When in the half-cocked position, the trigger does not function. In order to drop the hammer the remainder of the way, I need to thumb the hammer back and then operate the trigger to get the hammer to return to the uncocked position.

The Springfield 1911 and EMP also have the quarter-cocked position. That's probably a bad name for it because in this position, the hammer face is about ten degrees off of vertical. In this quarter-cocked position, a trigger pull will drop the hammer on both of these guns.

The Springfield 1911 (Legend Series) does not have a half-cocked position. I tried finding it both by thumbing the hammer and by a controlled release. I have no idea whether this is by design or a defect.

 

[1911Tuner]

Did you miss the part where I said "typically, that requires something to be broken?"

I caught that, but you followed with:

...but not always. What happened now and then was that edge of the sear would rest the edge of the 1/2 cock notch, outside the notch proper.

If the sear won't reset and grab the half-cock, it won't reset and grab the hooks.

In the cavalry, the SAA was discharged more than once when a trooper threw the stirrup down, hitting the hammer, shearing the "safety notch" and firing.

If a cavalry trooper did that, he was in violation of protocol. The first notch on a SAA was only for those times when action was imminent, or the trooper's gut told him to load the empty chamber, and it provided a means to keep the hammer nose off of a primer. A "stand by" or an "at the ready" postion if you prefer. It was never intended to be a "safe carry" position, regardless of what Cimarron's little book calls it.

A blow to the 1911 hammer at 1/2 cock would do the same thing.

It would require quite a bit more of a blow than one to the SAA to do that. That notch isn't anywhere close to as fragile as the quarter cock on an 1873 SAA. I've never tried it with a new-age cast or MIM hammer...but the old steel hammers will take quite a few hammer blows to damage the half-cock. Ask me how I know.

When the hammer is at half-cock, a blow to the hammer spur drives the sear into the bottom of the notch and toward the hammer...not against the lip. The hammer is moving in the wrong direction to transfer a shearing force to the lip. You may shatter the sear, and you may bend or break the sear pin, but it's not likely that you'll break the lip from the notch without a pretty heavy hammer.

Now, this does require the person to improperly keep pressure on the trigger as the hammer is lowered to get the sear in that position. With the sear resting on the 1/2 cock edge, the travel arc is even greater than when 1/2 cock is properly engaged.

If pressure is kept on the trigger, the sear will generally miss the half-cock altogether. It takes some deliberate and careful manipulation to "stand it on the edge." Just release the trigger as soon as the hammer is past full cock and you won't have a problem.

And...Even if you manage to do that inadvertently...it would still require that you pull the trigger to get the hammer to fall. Who places a loaded pistol in a "Safety" mode and starts pulling the trigger?

Go ahead and try it, as it sounds like you've never done so.

You might be surprised to know what I've done with and to a 1911 pistol in the last 50 years.

The fire control group isn't locked by the thumb safety. It blocks the sear's movement, and that's about all. It will not block the hammer's fall should the sear suddenly turn to dust. The "locked" part of Cocked and Locked refers to the slide...nothing in the trigger/fire control group.

In the half-cocked position, the fire control group is locked. The sear is captive and interlocked with the hammer. In many, even the trigger is caught fast. The sear can't move, and you can pull the trigger until the stirrup bends or breaks in the attempt. The hammer is positively stopped by the position of the sear in the bottom of the notch, so the hammer can't fall except by the vigorous application of a 4-pound sledge hammer...and who would that anyway?

The captive half-cock locks it all up, and that, mah fren, fits the description of a safety.

 

[1911Tuner]

Anyway...I went and did a little research on the ACII. Got a pretty good picture of a replacement hammer for the ACII, and it does appear to have a flat quarter-cock shelf instead of a to spec captive half-cock...so the OP's pistol is probably okay.

 

[AC1911]

Tuner, they are based on the series 70 design with the half-cock notch. I tried to take a pic of my hammer but my phone won't focus that close. It has a notch to capture the sear. I can pull the trigger as hard as I want and the hammer doesn't move. Something is wrong with the OPs gun.

 

[GLOOB]

The 1/4 cock stop doesn't require a hard pull to dislodge.

IME, when on 1/4 cock, a Series 80 requires a much harder trigger pull than when fully cocked.

The lower "1/4" cock shelf is an obvious improvement. If a round could fire from the original halfcock, then guess what happens if your thumb slipped just before the original halfcock was engaged?

If pressure is kept on the trigger, the sear will generally miss the half-cock altogether. It takes some deliberate and careful manipulation to "stand it on the edge." Just release the trigger as soon as the hammer is past full cock and you won't have a problem.

I can see this happening accidentally once in a blue moon if the user is unaware of the possibility and thinks the halfcock notch is a viable safety. Bottom line is that it never was as safe as hammer fully down, no matter what JMB intended.

 

[Jim Watson]

I am pretty sure the hammer with non-captive engagement, here being called "1/4 cock", was introduced by Colt with the Series 80 firing pin block guns. They call it a "safety stop."

A number of other makers have followed suit, I suspect because it simplified the machining (or moulding) a bit and saved them some money.

Strangely enough, I have seen a Springfield hammer with BOTH undercut half cock AND "safety stop." I don't know the point of that. Maybe a fallback position to protect those who go by fictional private eye Mike Hammer's example and carry in half cock.


I am not aware of a 1911 hammer being bashed out of half cock hard enough to fire the round. Maybe the same people who found all those drop-fires could do it.

On the other hand, Ruger lost or paid settlements on a number of lawsuits by people who carried an Old Model with conventional lockwork with the hammer in quarter cock over a loaded chamber and managed to set it off. It got to be cheaper for them to change the design than to pay off the klutzes.

And back in the old days, we were regularly warned in print of the dangers of "false half cock" single action revolvers and especially lever action rifles. Getting the sear tip on the lip of the half cock instead of in the undercut was remotely possible but very dangerous.

 

[David E]

If the sear won't reset and grab the half-cock, it won't reset and grab the hooks.

Totally and completely irrelevant to my point.

When the hammer is at half-cock, a blow to the hammer spur drives the sear into the bottom of the notch and toward the hammer...not against the lip.

No kidding.

Even if you manage to do that inadvertently...it would still require that you pull the trigger to get the hammer to fall.

Except that it doesn't.

You might be surprised to know what I've done with and to a 1911 pistol in the last 50 years.

Actually, I'm surprised at what you have not done.....like see how easy it is to rest the lip of the notch on the sear.

The captive half-cock locks it all up, and that, mah fren, fits the description of a safety.

Clearly, you need to correct Colt.

On page 16 of the Series 70 owners manual it warns "the half cock notch is not intended to be engaged by hand." then it has a caution warning about the very thing I've been talking about how hazardous the lip of the notch perched on the sear can be.

Colt has considerably more than 50 years experience with 1911's and have heard 1000's and 1000's of experiences with them from the people who use them.

But enough of that rabbit trail.

Should a hammer be able to disengage from 1/2 cock if nothing is broken?

No, not without considerable effort causing a breakage.

Should a hammer fall from the 1/4 cock shelf if the trigger is pulled?

Yes, it's designed that way.

For the OP to determine if he has a problem, he needs to know what kind of hammer or safety notch it has.

On one last note, let's say you have a chamber loaded 1911. Which is safer, pounding on a hammer set on 1/2 cock, or one fully forward?

 

[1911Tuner]

Bottom line is that it never was as safe as hammer fully down, no matter what JMB intended.

If the hammer can't fall, it can't fall, but no loaded gun can ever be completely safe.

I am not aware of a 1911 hammer being bashed out of half cock hard enough to fire the round.

Nor am I. You can manipulate the hammer and trigger until the sear 'stands on the edge" and slap the gun with your hand in any direction you can think of, and it won't release the hammer. I guess if it was dropped onto concrete from 6-8 feet, it might.

And back in the old days, we were regularly warned in print of the dangers of "false half cock" single action.

Yep. One must be careful and do it right.

Tuner, they are based on the series 70 design with the half-cock notch.

Good to know. Apparently the pictures are generic. I've only seen one American Classic, and it wasn't a II.