hammer drops to half-cock


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sophijo
February 16, 2010, 07:27 PM
This 1911 cycles; ejects and chambers cartridge, slide all the way closed and hammer is at the halfcock notch. Happens 3 times in 110 rounds; 1time with manufactured 230 gr RN FMJ ( 1 out of 10 of these rounds , and 2 times with my loads, 230 gr LRN, 5.6 gr W231, OAL at 1.255, Lee factory crimp die.

This is a series 70 Fusion BTW, and if I manually set hammer at halfcock I can release it with a trigger pull and it will fall.

Is the hammer falling from full cock or not going all the way to full cock position? Could this be a "Limp wrist" issue?

Can't figure this one out! Any thoughts appreciated!

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navyretired 1
February 16, 2010, 08:00 PM
Looks like you've got a damaged or bubba'ed hammer, there's no way you should be able to pull trigger and make hammer fall from half cock. It is a captive stop for stopping just that problem. Dangerous!!

1911Tuner
February 17, 2010, 07:56 AM
This 1911 cycles; ejects and chambers cartridge, slide all the way closed

We know from this that the hammer is being moved far enough to cock.

You may have a bubbasmiffed hammer issue, or it may be something much simpler.

Check to see if the sear is resetting cleanly. Free sear movement, or sticky? Enough tension on the sear spring's far left leg? Bending and tweaking the sear spring's left and center legs is on of those little things that a trigger smith does to lighten the trigger pull. Sometimes they take it a little too far. Some of them even flatten the bow in the main part of the spring.

If you can get hold of a new, unaltered sear spring and put it in the gun, you can determine whether your problem is simple, or a little more involved.

If that's not it, the dieconnect may be whence the bug lies. If the slide barely cams it down far enough to become disconnected, leaving the corners in even light contact with the corners of the sear feet...it can be the cause of an occasional hammer followdown by not allowing the sear to reset in time to grab the hooks...but is slipping off in time to grab the half-cock notch. If this is it, the cure may be something as simple as stoning a burr off the sear feet or the disconnect spade...or it may require a new disconnect.

Look for the simple things first. Most of the time, it's somethin' simple.

sophijo
February 17, 2010, 08:15 AM
Many thanks!! Last night I stripped and detail cleaned it and did find the tiniest (word?) burr on the disconnect spade. Couldn't see but could feel it. Stoned it off ever so gently and will try it out this weekend or next Tuesday for sure.
This is my first 1911 "problem solving" and am having more fun than a barrell of Sphinx kittens.
Thanks for your help!
Dave

1911Tuner
February 17, 2010, 08:31 AM
Howdy Dave.

Since you know the ropes on the detail strip, you can go ahead and do a disconnect function test.

Assemble the gun without the grip safety so you can watch the disconnect movement.
Under a good light, with the slide in battery...the top of the spade should overlap the front of the sear feet a little. Hold the trigger back and slowly move the slide...closely observing the disconnect. If should drop enough to get the top of the spade under the sear feet with a little clearance. It doesn't have to be much, but it needs a little so that the sear can reset freely into the hammer. Still holding the trigger, ease the slide forward to battery, and release the trigger. The disconnect should move forward and up into the connected position...between the sear and the trigger stirrup.

rcmodel
February 17, 2010, 10:49 AM
series 70 - if I manually set hammer at halfcock I can release it with a trigger pull and it will fall.Regardless of what else is wrong, you should not be able to make the hammer fall from the half-cock (intercept notch) by pulling the trigger.

The sear nose should be trapped in the intercept notch until you pull the hammer back enough for it to come out.

You have a damaged sear or hammer hook, and the gun is not safe to use until you fix it by replacing one or the other, or both..

rc

1911Tuner
February 17, 2010, 10:56 AM
The sear nose should be trapped in the intercept notch until you pull the hammer back enough for it to come out.


Unless it's got a shelf instead of a true captive notch. He mentioned that it's "Funsion Series 70" and not a Series 70 Colt. Many people say Series 70 when they're trying to convey that it doesn't have the Series 80 firing pin safety parts, even when they don't have a Series 70 Colt...or even a Colt for that matter.

SlamFire1
February 17, 2010, 10:58 AM
Dangerous!

Most likely your hammer notch is worn. Could be a combination of hammer and sear.

Are your trigger parts MIM? My Kimber trigger parts were MIM, the hammer did exactly the same as yours, and I have them replaced with forged parts.

rcmodel
February 17, 2010, 11:23 AM
Unless it's got a shelf instead of a true captive notch.Good point!

I think he first needs to establish if he has a Series 70 hammer with a real intercept notch, or a Series 80 hammer with the stupid bump thing.

If it's the former, it's broke beyond fixing without a new hammer or sear, or both.

If it's the latter, the "bump" is working normally, as far as it goes.

rc

sophijo
February 17, 2010, 12:21 PM
Thanks again. I will followup on all this and get back. BTW this is a new gun; January with -1k through it. Fusion which has a good rep and good customer service. I'd like to get it fixed ofcourse but am really looking forward to the "learning experience" that goes with working my way through it, with your help; and your help is invaluable and much appreciated. I can see that before the internet, if you didn't know someone you'd be up against it!

1911Tuner
February 17, 2010, 12:25 PM
That's what I suspect, rc. Lately, I've seen several aftermarket hammers with a simple shelf instead of the full captive notch, and some of them are narrowed shelves, reminiscent of the old Bullseye modification on the half-cock notches that prevented damage to the sear's engagement surfaces.

I guess since almost nobody uses the half-cock as a safety any more, they figured there was no sense in the extra machining step to make a captive notch. The shelf does arrest the hammer, and is all that's really necessary for that anyway.

rcmodel
February 17, 2010, 12:37 PM
Yea!

The "half cock" intercept notch was never a safe way of carrying a loaded 1911 in the first place.

But it seems a lot of folks just couldn't understand that.

And my prejudices aside, I suppose the bump is a good thing to protect us against ourselves. And the manufactures against us suing them.

rc

1911Tuner
February 17, 2010, 12:47 PM
Well...I've always had my suspicions about that, rc. I think the half-cock was intended to be a safety. If all it was meant for was a hammer blocker, it could have been much simpler, faster and cheaper to make by just using a squared shelf...like the Series 80 design. That would eliminate a machining step, along the the setup and the tooling required to make the cut, as well as freeing up a machinist to do other things.

Look at what it does when the hammer is on half-cock.

The hammer and sear are interlocked. The trigger can't move...the sear can't move...and the hammer can't move. The entire group is disabled until the hammer is cocked. If that doesn't fit the requirements for a safety, I'd like to know what does.

rcmodel
February 17, 2010, 01:05 PM
I can't know what the intent was, so I can't argue with your logic.
You are very likely correct.

But there are only two positions from which the hammer cannot break something internally from an impact and fire a chambered round.
1. All the way down against the slide.
2. All the way back cocked & locked and protected by the grip safety spur.

The middle "safety" notch exposes the hammer spur to impact that "could" break something internally and allow it to fire a round.
Whether it has or not, I can't say.

But it seems to me the intent of the Series 80 hammer bump was to keep folks from doing it in the first place, not to save manufacturing costs.

rc

1911Tuner
February 17, 2010, 02:01 PM
I understand all that. I've never used it as a safe carry condition, and don't recommend it to anyone...but just going on the way that it all locks together, it makes me wonder exactly why it was done that way. It seems to be deliberate rather than coincidental.

So, assuming that it was deliberate...it raises the question: "Why?"

Colt's much simpler Series 80 redesign was clearly meant to be no more than an interceptor, and placed the hammer too close to the slide to let the gun fire if the trigger is pulled. The original was placed far enough back to let it fire...so it was made captive in order to prevent that.

And...That's the way that Browning designed all his other exposed hammer guns. Others that used a half-cock safety come to mind, the most prolific being Winchester's original Model 1894 rifle and Model 1897 shotgun...both were hammer/sear/trigger disabling functions.

Finally...guns aren't designed to be dropped. The 1911 pistol had a lanyard loop for a reason.

Anyway...It's largely a matter of conjecture, and straying a bit off-topic.

sophijo
February 17, 2010, 05:11 PM
I spoke with Bob Serva, owner of Fusion and previous Dan Wesson bigwig and nice guy, today. He said its a Series 70 hammer and to ck the disconnect and perhaps some added tension on the middle leaf of the sear. So got an exciting week end coming up what will all the recommendations!

Thanks for your help!
Dave

rcmodel
February 17, 2010, 05:24 PM
Again, if it truly is a series 70 hammer, there should be no way the sear nose can slip out of the intercept notch when you pull the trigger unless the hammer or sear is broke.

The only other possibility is the sear nose is too thick to fit in the intercept notch in the hammer and is just setting on top of it.
Still a major safety concern.

Look it over very carefully when you get it apart.

rc

1911Tuner
February 17, 2010, 05:47 PM
The only other possibility is the sear nose is too thick to fit in the intercept notch in the hammer and is just setting on top of it.
Still a major safety concern.

While a sear too thick to fit into the notch...or the notch too narrow to allow the sear crown to enter isn't proper function...I can't understand why it would be a safety concern. If the trigger is deliberately pulled, the worst the gun could do is fire...and if it's deliberate, it's assumed that it's expected to fire, and will be pointed downrange. As long as the notch arrests the hammer, it's doing what it should do in preventing the gun from burst-firing or firing unexpectedly during a reload or initial loading.

The hammer followdown is the concern, should the sear not catch the hammer should the hammer fall without the trigger being pulled

For the record...and for sophijo's knowledge base...Series 70 has nothing to do with the hammer design. Until the Series 80 redesigned half-cock came along, the hammers were pretty much the same from 1911 until 1983, with variation in spur length and width. Series 80 and Series hammers are fully interchangeable. Series 70 designated the collet bushing and "Accurizer" barrel. All Series 70 guns were 5-inch guns...either Government Model or Gold Cup. No Series 70 Commanders or Combat Commanders were produced.
Neither are there any Series 70 Springfields or Kimbers or Rock Islands.

Colt Pistols built prior to the introduction of the Series 70 run were just Government Models...Gold Cups...or Commanders. These guns built in the 50s and 60s weren't called Series 50 or Series 60 and more than the guns built from 1911-1919 were called Series Teens.

1911Tuner
February 17, 2010, 05:52 PM
I spoke with Bob Serva, owner of Fusion and previous Dan Wesson bigwig and nice guy, today. He said its a Series 70 hammer and to ck the disconnect and perhaps some added tension on the middle leaf of the sear.

Call him back and ask him if the hammer has a captive half cock notch or just a stop shelf. If it's captive...like rc said...it shouldn't allow the hammer to fall when you pull the trigger.

navyretired 1
February 17, 2010, 06:26 PM
I repeat what I said at first, the half cock notch is meant to catch a hammer which is falling from full cock without trigger pull and CAN'T BE PULLED OFF BY TRIGGER WHEN IN CAPTIVE NOTCH. The purpose JMB was thinking of was as a passive safety catch not a safety to be used or manipulated in any way by operator.
I can't beleave that OP can't see damage to sear or hammer if he can feel burr on disconnector the half cock outer wall should be completely missing if he can pull trigger from half cock position.

1911Tuner
February 17, 2010, 07:13 PM
the half cock notch is meant to catch a hammer which is falling from full cock without trigger pull and CAN'T BE PULLED OFF BY TRIGGER WHEN IN CAPTIVE NOTCH.

We understand, aknowledge, and accept that...but there are some half-cocks that aren't captive, and will let the hammer fall if the trigger is pulled. This is part of what we're trying to ascertain.

The purpose JMB was thinking of was as a passive safety catch not a safety to be used or manipulated in any way by operator

And you know this...how? Have you spoken with Browning?

We can't determine his true intent with any certainty. All we can do is look at the function of a given part or group of parts and draw a conclusion based on what they actually do, rather than what we believe that they were intended for. Again...When the sear is trapped in the captive notch, the whole trigger/fire control group is effectively disabled. If that doesn't meet the criteria for a safety, I don't know what does. Since the captive notch requires a fairly complex machining operation...it would seem that the function was deliberate...and unnecessary if all it had to do was act as a passive, hammer arresting safety. A simple square shelf would have served the purpose as well as the captive notch, and it would have been a lot easier to create. Easier is faster. Time is money.

1911Tuner
February 17, 2010, 08:11 PM
The best way to settle this argument and get the thread back on topic is to go directly to the patents. Section 7 in the second paragraph, it's stated:

"With the hammer drawn to the firing position...should it becomes necessary to lower the hammer into the safety position without allowing the hammer to come into contact with the firing pin..."

So, it appears that Browning did, in fact, intend for the half-cock to perform as a safety position as well as a passive hammer arresting device...true to his habit of redundancy and having a single part perform a dual function.

Go and read it for yourself.

http://www.google.com/patents?id=NdRdAAAAEBAJ&printsec=abstract&zoom=4&source=gbs_overview_r&cad=0#v=onepage&q=&f=false

1911Tuner
February 17, 2010, 10:31 PM
....and you coulda heard a pin drop...

:)

Kruzr
February 17, 2010, 11:10 PM
To the OP, does the trigger have an overtravel screw?

1911Tuner
February 17, 2010, 11:18 PM
To the OP, does the trigger have an overtravel screw?

Unrelated, Kruz. He's got hammer followdown after firing...not catching on the half-cock and failing to fire.

Little somethin' in the patents for you, too. Lemme go see where it is.

Kruzr
February 17, 2010, 11:20 PM
Yep, you're right, I was thinkin' about why it was dropping from a captive half cock notch (if it is a captive one.)

Little somethin' in the patents for you, too. Lemme go see where it is.
I've read it, it talks about "momentum" of the slide. :D

(Lines 20 - 50 or so?)

1911Tuner
February 17, 2010, 11:31 PM
Nah. Section 5, paragraph 25.

navyretired 1
February 18, 2010, 05:35 AM
If a simple shelf would have done the trick the series 80 hammer wouldn't have that ugle wedge sticking out. When the trigger is being pulled the sear is out of position to stop the sear in either case. If that were not so every time you pulled trigger the sear would bang against safety notch. When thumb cocking you drag the finely tuned sear surface across safety notch which can and does destroy a trigger job or a normal trigger sear surface, which is why its a good but ugle idea to hold trigger back if thumb cocking, don't forget to let go of trigger before hammer if you don't want a bad day, or preferly don't thumb cock weapon, it's never really safe and we all know we cock and dry fire weapon. To fix this problem Colts decided to put that wedge in because it will still stop a falling non-trigger pulled hammer but will also not batter the area of fitted sear surface which is normally mated to hammer.
I make no claim of knowing what was on JMB mind but as an engineer I can look at a mechanism and figure out how it works. We're arguing apples and oranges and not getting answers to questions ask of OP so a proper troubleshooting can accur. His initial statement that a trigger pull will drop hammer from half cock is kind of hard to beleave as normal trigger geometry doesn't work that way. I've never had a complaint on my government model work. Long distance troubleshooting is hard at all times and without the answers to questions ask it's almost impossible. BTW I think almost anybody would answer the series 70 style hammer if ask is it the series 70 or 80 which was the question I think. Most GM pistol smiths know what the series 70 changes were and I for 1 don't care for collet bushing. The only comeback I've ever got besides (not 3 1/2 Lb) is for a broken finger in a Steel Challange match in 1985. It took a whole day to get that gun apart without destroying it.
Navy

1911Tuner
February 18, 2010, 06:12 AM
We did asnwer the OP's questions as far as we could go with it. Now we wait and see what was causing his problem.

I didn't start this. All I did was suggest...merely suggest...that the half-cock notch might be an intended safety, and stated the reasons why I thought so. Turns out that I was right.

And why would thumb-cocking the gun destroy the sear? The hammer drags across the
off side...where the breakaway angle is often cut in the process of doing a trigger job...and never touches the primary surface. So, how can dragging against the hammer on the same place where many smiths deliberately stone a relief destroy the sear...match tuned or otherwise?

And why would anybody pull a trigger before thumb cocking a hammer on any gun? I fail to see how that would be a "good idea" under any circumstances.

Finally...I didn't whizz on your shoes. I stated a theory...rc challenged it...I responded with my reasoning and analysis...you backed up his response...I looked in the patents and found that the half-cock was indeed a safety, by design and intent. Are we to assume that Browning was an idiot who didn't understand his own gun?

Anyway...We wait to see what bug was nesting in the OP's fire control group. We've pretty well got it narrowed down to disconnect or sear spring.

sophijo
February 18, 2010, 08:35 PM
Just noticed today during minor "fiddling" before work that with hammer at half-cock notch I can push on the hammer and it will depress a little with an audible "click", after which it will not fall when I pull the trigger. Pull the hammer back to full-cock, release it manually to half-cock and it will fall when I pull the trigger. I will inspect more thoroughly this weekend. BTW after reading your thoughful posts I'm wishing the good Lord had granted me a few more IQ points!!

1911Tuner
February 18, 2010, 11:26 PM
That sounds like the captive notch itself isn't to spec. The sear should enter easily and be trapped. Since I don't know what Fusion's sears or hammers look like, I guess the sear could also be a player. Pretty much a non issue unless you intend to use the half cock as an active safety. As long as it grabs the sear during a free fall, it's doing what it's supposed to.

Dunno why these manufacturers can't seem to get the specs and dimensions right. It ain't like they can't find an old USGI pistol or a pre-Series 70 Colt to reverse engineer.

sophijo
February 19, 2010, 11:49 AM
The half -cock issue and the hammer follow are unrelated.
The hammer either has a half-cock notch or a shelf on which the sear nose catches when hammer follows. If its a notch, that may be out of spec. Could be the sear nose.
>The hammer follow is one of the following or a combination;
>Middle leaf spring tension too light
>Sear/hammer fitment damaged
>Disconnector issues.
I need some help with the disconnector involvement. I've watched the STI animations, read here, and Kuhnhausen and still having a tough time getting it.
Could the trigger over-travel be too deep?

rcmodel
February 19, 2010, 12:29 PM
Put the gun together without the grip safety.

Without it in the way, you can watch the disconnector work.

rc

Old Fuff
February 19, 2010, 12:37 PM
Dunno why these manufacturers can't seem to get the specs and dimensions right. It ain't like they can't find an old USGI pistol or a pre-Series 70 Colt to reverse engineer.

They don't even have to buy a gun, because the USGI blueprints and material specifications are available - but I can tell you this, any relationship between those prints, and the guns being made today is to say the least, unexpected and unlikely.

Maybe that's the reason so much of the new stuff simply doesn't work. :banghead:

1911Tuner
February 19, 2010, 12:39 PM
Could the trigger over-travel be too deep?

Unless the trigger's stop surface in the grip safety is way out of spec, it can't go so deep that it would interfere with the disconnect reset. This isn't to say that the stop surface isn't out of spec. I've seen one that was, but can't remember whose grip safety it was.

Just for sheets and geegles, look to see if the center leg of the sear spring has a slight kink in it, about 1/8th inch from the top. Also have a peek at the angled portion at the rear on the disconnect spade...where the spring rides. Is it straight, or concave...like it's been scraped out?

sophijo
February 21, 2010, 05:30 PM
I completed the clean/ inspection today using this tutorial:
http://how-i-did-it.org/detail-1911/frame_detail.html
It's well-done.
I didn't see anything that was obviously wrong other than some crud, but then again don't have an expert eye!
The half-cock notch did have a small radius at the inside corner, as if the cut hadn't been quite completed. I, very gently, stoned that square, and added a smidgen of tension to the center leaf on the sear spring.
No irregularities on the sear that I could see.
I didn't see any of the wear on the disconnecter that Tuner hadn't mentioned to look for.
I'll shoot Tuesday and see what happens!
Thanks again for you guidance.
Dave

sophijo
February 23, 2010, 08:38 PM
I stripped it again after some more reading.
Added some tension to the left leaf too.
Noted the the disconnector "tongue", which contacts the trigger, was sharp. You could probably cut your finger on it. The sharp edge was not square with the sides either. Don't know if that matters functionally but it does look genky.
The sear nose appears, under magnification, to be almost radiused instead of having an acute edge as seen here on another thread. It almost looks as if there was an edge which had been worn, but I only have 1k rounds through it and an equal number of dry-fires. Not having those critcal fitment skills I left it, but will study it. Been dreaming about EGW action pack!
Backed out the trigger over-travel screw just to rule out that.

Shot 50 Fiocchi 230 FMJ, and 50 200 LRN, through it today and got three "follows" to the halfcock notch. I noticed on the first one that I had "limp" wristed" and was able to recreate that drop 2 more times with a loose grip. Otherwise it was 100%.

BTW I used my Dan Wesson CBOB as a comparison and it ran comparable rounds without issue. I haven't detailed that gun but will ASAP as that would be a great comparison.

Thanks
Dave

1911Tuner
February 23, 2010, 08:44 PM
The spring tip absolutely can have a bearing on the issue. It should be lightly beveled and polished smooth...and square...and it needs to contact the spade at the right place, neither too high nor too low. Too high and pulling the trigger forces the disconnect out of position,and the hammer sotps at half-cock/failure to fire. Too low, and it can interfere with disconnect function...which interferes with proper sear reset...and cause hammer follow. In extreme cases, it cac cause burst/full auto fire. That's why I asked you earlier if the spring leaf had a slight kink near the top.

Sounds like you need a new sear spring that's been correctly prepped.

rcmodel
February 24, 2010, 12:23 PM
It almost looks as if there was an edge which had been worn, but I only have 1k rounds through itMany of which allowed the hammer to drop to half-cock apparently.

Your sear is damaged now, and you are fighting a losing battle until you get a new sear, or a sear jig and repair the one you have.

rc

sophijo
March 4, 2010, 10:57 PM
New sear, disconnector, sear spring, hammer/strut arrived today. Install pretty straight-forward except for binding pins in sear and hammer both. Polished them with 1000 grit paper until they fit smoothly. "Dry" tests look like the half-cock issue has been resolved. Take-up increased to about 035+. I'll shoot next Tuesday and as they say, "the proof is in the putting" or is it pudding(?). Thanks for you help! I'm feeling pretty spiffy!!

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