1911Tuner
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Yep, Jim. A picture would be worth 10,000 bytes in this case.
1911 Half Cock Discharge... Help!
- Thread starter Duelist
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Carl N. Brown
Member
My AutoOrdnance 1911A1 pistol has the half cock notch that captures the sear.
My sons Paraordnance 45 auto has the shelf (which catches the hammer if it slips under the thumb when cocking) but which does not function as a half-cock notch. It was a startling discovery for me: you could pull the trigger and the hammer would fall from "half-cock".
But since carry loaded half-cock was not a design parameter of the original 1911, and is not recommended, the sole purpose of a half-cock shelf or notch should be to catch the hammer if the hammer slips from under the thumb before reaching full cock.
ADDED: My drill with the .45 was either hammer down on empty chamber or cocked safety up if loaded chamber. I was taught that carry loaded half-cock was not a option; maybe JMB had other design intent is another question.
SCOND THOUGHT: Although the opening post is titled 1911 Half Cock Discharge... the poster describes the hammer falling from half cock but does not actually describe a discharge, just a potential. I am tempted to borrow my son's Paraordnance with the "shelf", load a couple of primed cases (no powder or bullet), and see if the hammer has enough momentum to actually fire: the 1911 design has an inertial spring loaded firing pin after all, and does require a healthy mainspring for reliable ignition with all ammo types from full cock.
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1911Tuner
Moderator Emeritus
Para Ordnance uses a direct copy of the Colt Series 80 firing pin block.
Quote:
"But since carry loaded half-cock was not a design parameter of the original 1911, and is not recommended, the sole purpose of a half-cock shelf or notch should be to catch the hammer if the hammer slips from under the thumb before reaching full cock"
And...that's not exactly true, Carl. As I've tried to explain several times...the original intent was to use the half-cock as a safety...carried or stored. That's how Browning designed all his other exposed hammer guns.
Again...Not advising you to use it. Only that it was the designer's intent.
Let's break it down. I knew it was a safety before I read it in the patents...because of what it does and because of what it takes to machine it.
It interlocks the hammer and sear and disables the fire control group. Nothing can move. Hammer...Trigger...or sear. That alone makes it a safety.
Drawing on my knowledge of machining and mass production, I can see that the captive half-cock notch requires a fairly complex machining process that includes
setup...tooling...and man-hours to accomplish.
Why go to all that trouble if all they wanted to do was to create a means to stop an escaped hammer? It doesn't follow logic to make it more complicated when a plain, square shelf such as the one on the Series 80 hammer would have sufficed, and it would have been simpler...faster...and cheaper to machine than the captive notch.
Only German engineers are noted for making things more complicated than they need to be. Browning liked to simplify...which is why he often gave one part two or more functions.
Quote:
"But since carry loaded half-cock was not a design parameter of the original 1911, and is not recommended, the sole purpose of a half-cock shelf or notch should be to catch the hammer if the hammer slips from under the thumb before reaching full cock"
And...that's not exactly true, Carl. As I've tried to explain several times...the original intent was to use the half-cock as a safety...carried or stored. That's how Browning designed all his other exposed hammer guns.
Again...Not advising you to use it. Only that it was the designer's intent.
Let's break it down. I knew it was a safety before I read it in the patents...because of what it does and because of what it takes to machine it.
It interlocks the hammer and sear and disables the fire control group. Nothing can move. Hammer...Trigger...or sear. That alone makes it a safety.
Drawing on my knowledge of machining and mass production, I can see that the captive half-cock notch requires a fairly complex machining process that includes
setup...tooling...and man-hours to accomplish.
Why go to all that trouble if all they wanted to do was to create a means to stop an escaped hammer? It doesn't follow logic to make it more complicated when a plain, square shelf such as the one on the Series 80 hammer would have sufficed, and it would have been simpler...faster...and cheaper to machine than the captive notch.
Only German engineers are noted for making things more complicated than they need to be. Browning liked to simplify...which is why he often gave one part two or more functions.
Duelist
Member
@1911 Tuner: The hammer still falls when pressure is put on the back of the spur and the trigger is pulled. I did notice something interesting, however: If you pull the slide back a tiny bit (1/4") the hammer will click into position, and be unaffected by the trigger. The trigger will move, but the hammer will not fall. Thumbing the hammer further back, the half cock notch will engage, and the hammer will fall when the grip safety is depressed and trigger pulled. The half cock would still "catch" the hammer when I cocked the hammer, held the trigger, let the hammer forward, and released the trigger.
I will be bringing it down to the local 'smith shortly, just to make sure this is not a side effect of something else.
I will be bringing it down to the local 'smith shortly, just to make sure this is not a side effect of something else.
1911Tuner
Moderator Emeritus
Duelist...It sounds like you've got a hammer that features both a quarter-cock shelf and a half-cock notch...like Springfield's weird hybrid design.
Pulling the trigger when the sear is on the shelf will drop the hammer. If it's in the half-cock notch....it won't.
Quote:
"The half cock would still "catch" the hammer when I cocked the hammer, held the trigger, let the hammer forward, and released the trigger."
If I'm reading this right...it also sounds like you've got an overtravel screw that needs to be backed out a half-turn or so. Holding the trigger and lowering the hammer...the hammer shouldn't encounter anything on the way down.
Pulling the trigger when the sear is on the shelf will drop the hammer. If it's in the half-cock notch....it won't.
Quote:
"The half cock would still "catch" the hammer when I cocked the hammer, held the trigger, let the hammer forward, and released the trigger."
If I'm reading this right...it also sounds like you've got an overtravel screw that needs to be backed out a half-turn or so. Holding the trigger and lowering the hammer...the hammer shouldn't encounter anything on the way down.
Duelist
Member
Thanks everyone!
1911Tuner
Moderator Emeritus
Ah! We thought you were gonna take a stab at fixin' it yourself.
Let us know what the smif finds.
Let us know what the smif finds.
I don't want to get caught in the crossfire, but the most common cause of a hammer suddenly falling off the half cock is that the half-cock notch is broken out. The cause is usually a sear that is too large and the wedging effect breaks out the notch if the hammer is struck or the gun dropped on the hammer.
Mating the sear to the hammer is part of the general checkup for a 1911 type with a half cock notch.
Jim
Mating the sear to the hammer is part of the general checkup for a 1911 type with a half cock notch.
Jim
1911Tuner
Moderator Emeritus
Jim...Yep. That's why we kept askin' for a picture of the hammer. Gotta know what we're workin' with.
Okay, this explains and shows the trigger does not have enough pre-travel to allow the hammer to fully engage when pulled to half cock with the trigger re-set and slide closed to battery. When the hammer is first pulled to half cock, and then the slide is pulled back just a bit, the disconnector is pushed down and this gives the sear more room to fully seat. When the slide is then released the trigger doesn't re-set as there isn't enough room.
This does not prove however whether the hammer is captive or not, just that the pre-travel isn't sufficient.
CAW
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I've read through this thread many times now and am very interested by the exchanges between CAWalter and 1911Tuner. I never miss an opportunity to learn something about the 1911, and the interaction between the trigger, sear, hammer (both notches), disconnector and sear spring in combination with over-travel and pre-travel is fascinating, albeit a little confusing. I can't stand the idea that my 1911s aren't optimized i.e. the best they can be. I don't want "good enough" ... I want "right" ... so ....
I tested my 1911s and only the Dan Wessons (Valor and V-Bob) have noticeable trigger movement with the hammer at half cock, and only the Dan Wesson triggers will reset following the procedure described in the second quote. The triggers of two Ed Browns and two Kimbers with Ed Brown sears/hammers have ZERO movement with the hammer at half cock. None of the triggers will reset following the procedure in the second quote. However, none of the six hammers will fall from half-cock if I pull the trigger with the grip safety depressed. I understand the concept that if there isn't enough pre-travel, the sear may not fully engage the half cock notch in the hammer. So basically, the half cock may work, but it's not the best it can be. I don't use the half cock "feature" so maybe I shouldn't care ... but I do. No one warned me that 1911s can cause obsessive behavior.
I've read through this thread many times now and am very interested by the exchanges between CAWalter and 1911Tuner. I never miss an opportunity to learn something about the 1911, and the interaction between the trigger, sear, hammer (both notches), disconnector and sear spring in combination with over-travel and pre-travel is fascinating, albeit a little confusing. I can't stand the idea that my 1911s aren't optimized i.e. the best they can be. I don't want "good enough" ... I want "right" ... so ....
CAWalter said:
CAWalter said:
I tested my 1911s and only the Dan Wessons (Valor and V-Bob) have noticeable trigger movement with the hammer at half cock, and only the Dan Wesson triggers will reset following the procedure described in the second quote. The triggers of two Ed Browns and two Kimbers with Ed Brown sears/hammers have ZERO movement with the hammer at half cock. None of the triggers will reset following the procedure in the second quote. However, none of the six hammers will fall from half-cock if I pull the trigger with the grip safety depressed. I understand the concept that if there isn't enough pre-travel, the sear may not fully engage the half cock notch in the hammer. So basically, the half cock may work, but it's not the best it can be. I don't use the half cock "feature" so maybe I shouldn't care ... but I do. No one warned me that 1911s can cause obsessive behavior.
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1911Tuner
Moderator Emeritus
If the trigger bow is so long...or if the pretravel tabs set to keep the trigger back so far...that the sear won't reset to a point that will allow the half cock to be engaged...the hammer wouldn't hold full cock, either.
Unless and until we can get a look at the hammer and determine whether it has a flat shelf...a captive notch...or a damaged notch...we're spinning our wheels here. It's a moot point anyway, because he's decided not to try and address the problem himself, and will be taking the pistol to a gunsmith to sort it out.
Unless and until we can get a look at the hammer and determine whether it has a flat shelf...a captive notch...or a damaged notch...we're spinning our wheels here. It's a moot point anyway, because he's decided not to try and address the problem himself, and will be taking the pistol to a gunsmith to sort it out.
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I've read through this thread many times now and am very interested by the exchanges between CAWalter and 1911Tuner. I never miss an opportunity to learn something about the 1911, and the interaction between the trigger, sear, hammer (both notches), disconnector and sear spring in combination with over-travel and pre-travel is fascinating, albeit a little confusing. I can't stand the idea that my 1911s aren't optimized i.e. the best they can be. I don't want "good enough" ... I want "right" ... so ....
I tested my 1911s and only the Dan Wessons (Valor and V-Bob) have noticeable trigger movement with the hammer at half cock, and only the Dan Wesson triggers will reset following the procedure described in the second quote. The triggers of two Ed Browns and two Kimbers with Ed Brown sears/hammers have ZERO movement with the hammer at half cock. None of the triggers will reset following the procedure in the second quote. However, none of the six hammers will fall from half-cock if I pull the trigger with the grip safety depressed. I understand the concept that if there isn't enough pre-travel, the sear may not fully engage the half cock notch in the hammer. So basically, the half cock may work, but it's not the best it can be. I don't use the half cock "feature" so maybe I shouldn't care ... but I do. No one warned me that 1911s can cause obsessive behavior.
One of the greatest values of following this thread and experimenting with your 1911s is an increased understanding of how it works and the parts relationship.
I use the half cock to set the pre-travel of a trigger so it will pass the reset test, but if the trigger has just the least amount of slack with the hammer in half cock, the sear has fully engaged the notch. All is well. The value of a little more to pass the reset test, is simply uniformity in my stable. And this is insurance against trigger bounce follow on light trigger pulls.
One thing I do to the very minimum is pull my trigger in half cock or even gently set the hammer in half cock. The sear nose primary and secondary have been polished and set for the also prepped full cock. The half cock is for a "what if" failure, why repeatedly set the unmatched half cock against the finely finished sear face. I know it may have actually been used as a safe position at one time, but with the understanding of the safest 1911 gun handling procedures it is best left as a fail safe only.
CAW
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The disconnector resets. The sear engages. If the pre-travel is too short to fully allow the sear to fully engage the half cock when the hammer is pulled there, it, the sear, can still fully engage the hammer hooks. As the floor of the hooks is not as close to the pivot center as the half cock.
It is easy to see that this is true by simply noting the amount of pre-travel a trigger has when in full cock and comparing to half cock. The reason there is less pre-travel in half cock is the sear has rotated deeper.
CAW
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CAWalter said:
I agree 100%!! You and 1911Tuner are providing many of us with an education. This 1911 stuff isn't trivial and it does require quite a bit of thought to understand what, how, why and where. Does the amount of pre-travel have anything to do with hammer follow and why the hammer wouldn't catch on the half cock notch in the event of the hammer following the slide forward? I've read that the hammer drops all the way with hammer follow but I don't understand why it wouldn't be caught by the half cock notch since the trigger isn't depressed.
Yes, pre-travel does contribute to hammer follow by trigger bounce. Whether it goes to half cock or not is iffy. Dropping the slide on say a mag with only a couple rounds which doesn't slow the slide as much as a full one, and with too little pre-travel follow is likely. Too little pre-travel, may not affect rapid fire when the trigger is held back anyway though.
CAW
I hope the OP and mods don't mind but I'd like to learn more about pre-travel with the hammer at half cock to get a better understanding of what's going on. As I mentioned, there's ZERO trigger movement with the hammer at half cock with four 1911s containing Ed Brown sears, hammers, disconnectors and sear springs. None of the triggers will reset following the procedure described in post #12. There is a little movement (pre-travel) of the triggers in both Dan Wessons and those triggers will reset following the procedure described in post #12. I don't know who makes trigger group parts for Dan Wesson but I disassembled one of the Kimbers and the Valor to compare the internals. I measured the thickness of the disconnector "ears" and the sear spring legs.
Ed Brown parts in Kimber
Disconnector ear thickness > 0.0335"
Sear spring leg thickness > 0.0285"
Valor
Disconnector ear thickness > 0.0350"
Sear spring leg thickness > 0.0285"
So the DW disconnector ears are thicker than the EB and yet the DW triggers have slack at half cock.
The half cock notch on the Ed Brown hammer is quite different (deeper) than the one on the Dan Wesson. The EB notch only contacts the sear in the center (about 1/3 of the sear width) whereas the DW notch contacts the sear across the total width of the sear. The disconnectors are different too. So is it possible that due to the geometry of the notch and/or disconnector that pre-travel may not be attainable with EB sears/hammers?
Some photos ...
Ed Brown parts:
Dan Wesson parts:
Ed Brown parts in Kimber
Disconnector ear thickness > 0.0335"
Sear spring leg thickness > 0.0285"
Valor
Disconnector ear thickness > 0.0350"
Sear spring leg thickness > 0.0285"
So the DW disconnector ears are thicker than the EB and yet the DW triggers have slack at half cock.
The half cock notch on the Ed Brown hammer is quite different (deeper) than the one on the Dan Wesson. The EB notch only contacts the sear in the center (about 1/3 of the sear width) whereas the DW notch contacts the sear across the total width of the sear. The disconnectors are different too. So is it possible that due to the geometry of the notch and/or disconnector that pre-travel may not be attainable with EB sears/hammers?Some photos ...
Ed Brown parts:
Dan Wesson parts:
Duelist
Member
My 'smith was unable to help, I will post pics later today
Duelist
Member
Duelist said:
Based on that photo, you could have used a Sharpie and we still wouldn't know!!
Anyway, the hammer hooks and half cock notch look similar to the one in my Valor ... nothing unusual ... right? On second thoughts, what's the dark spot in the half cock notch? Is there some kind of obstruction?
SSN Vet
Member
I think your reasoning has left out a couple of significant factors
1. length of the trigger bow will affect the pre-travel
2. the various frames may have slight variations in the relative positions of the hammer pin hole, sear pin hole and trigger track.
3. The Dan Wesson parts were installed by someone who does it for a living and thus were likely "fit". I'm assuming you dropped in the EB parts.
This is an innovative design (I beleive Colt first did this on their Gold Cups) that saves the sear surfaces (which are precisely stoned and fit) where they contact the hammer hooks, from damage when dropped hard on the half cock. Only the center portion (which does not play in the critical hammer hook to sear nose engagement) will land hard on the half cock notch and get beat up. So you won't trash your trigger job.
looks like a pre S-80 fully captive commander ring hammer to me. Most likely the stock hammer.
1911Tuner
Moderator Emeritus
And what was the gunsmith's reason for not being able to fix the problem? This thing ain't exactly a Swiss watch.
SSN Vet said:
Not much reasoning on my part and a significant error I'm afraid. However, both of my Ed Browns (built by Ed Brown or his elves) that I've done absolutely nothing to perform in exactly the same way, so that's why I asked if the lack of pre-travel has anything to do with the design of the Ed Brown hammer and half cock notch. I don't want to spend hours and hours trying to get my 1911s to pass the half cock trigger reset test if it's an exercise in futility.
I do have one confession to make. I completely misread CAWalter's point about "thinning the sear legs". I read it as the sear spring legs and couldn't figure out why they'd need to be thinned when they can be bent.
I just measured the sear legs with the following results:Ed Brown sear legs > 0.0915"
Valor sear legs > 0.0840"
My apologies for the confusion. Maybe it's worth the effort to thin the sear legs on the Ed Brown sear to see if it increases pre-travel.
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