1911 safety issue.

[mainiac]

Did a trigger job on a 1911 today,my 1st attempt ar 1911.came out very nice,crisp and 2lb,10oz pull.all safety checks were tried,and all works well,except....safety on,pull trigger,then switch safety off,and the hammer will drop,right past the halfcock notch.why would this do this,or what have i done?
Btw,,,polished all internals,didnt change any angles,,only real stoning was on the hammer hooks,,took them down to .0018,,,

[country gent]

Most likely there is enough "PLAY" in the mechanism that when you pull the trigger the safety is holding but the hammer moves past the notches allowing it to fall when the safety is released.
Another is the sear leg in the flat spring is weak or out of shape.

[1006]

I think you need a new safety fitted. I do not think you caused the problem. The safety was probably never fit as well as it now needs to be. When you polished up the action parts, I think the safety no longer had a tight enough fit to prevent the sear from traveling far enough to slip off the hammer hooks when the safety is switched off after the trigger is pulled with the safety engaged. The sear probably moved just as much during the test prior to your work, but now it is too much.

[DougGuy]

The sear was probably moving forward before you took down the hooks. Afterwards, the same amount of movement had the nose of the sear partially out from under the hammer hooks because the hooks were shorter. You should probably fit a new safety. I TiG welded and refiled the part on mine that keeps the bottom of the sear from moving.

[tazman]

I am not a gunsmith or 1911 mechanic. I had the same problem with a secondhand 1911 I had purchased a while back.
I took it to a gunsmith who was very good with the 1911 platform. It took him less than 10 minutes to fix the problem and he used the original safety.
I don't know what he did but I never had issues with that again.
I would suggest taking the pistol to a good gunsmith who is familiar with 1911 pistols.

[mainiac]

How can it do it,with the grip safety, not depressed,and how does it miss the half cock notch??

[Plate plinker]

Curious about gun brand?

Might buy a Harrison design fire control group.

[mainiac]

Curious about gun brand?

Might buy a Harrison design fire control group.

A ruger with many thousands ofrounds threw it.i may buy a new safety,or tig that edge up,,and file.

[Petrol & Powder]

I concur with 1006 & DougGuy, the safety was likely poorly fitted to start with and after the amount of engagement was slightly reduced, that flaw became evident.

A 1911 manual safety, when properly fitted, locks the sear AND blocks the hammer when engaged.

It shouldn't be too difficult to correct. Worst case scenario would be to fit a new sear and maybe a safety. Without having the gun in front of me, I cannot diagnose the problem with certainty, but the speculation by 1006 (post #3) seems highly likely to me.

[Plate plinker]

A ruger with many thousands ofrounds threw it.i may buy a new safety,or tig that edge up,,and file.

There ya go! Not familiar with ruger internals. Are the part MIM?

[Petrol & Powder]

How can it do it,with the grip safety, not depressed,and how does it miss the half cock notch??

The grip safety only blocks the trigger bow and the grip safety is not in play for the failure you describe in your first post. Once the sear has moved far enough to release the hammer (which you accomplished when you pulled the trigger with the safety engaged) the only thing holding the hammer is the manual safety. (because the safety likely wasn't properly fitted to start with). As for why the hammer is missing the half cock nock on the way down? There could be several reasons but none of them are relevant because the major failure needs to be corrected first. I suspect the sear spring is too weak to push the sear into the half-cock notch as the hammer falls but you need to correct the primary failure of the manual safety before you move onto the secondary problem of the sear missing the half-cock notch.
In the words of Abraham Lincoln, "One war at a time".

Correct the manual safety issue first and then seek out the other failures.

[mainiac]

The grip safety only blocks the trigger bow and the grip safety is not in play for the failure you describe in your first post. Once the sear has moved far enough to release the hammer (which you accomplished when you pulled the trigger with the safety engaged) the only thing holding the hammer is the manual safety. (because the safety likely wasn't properly fitted to start with). As for why the hammer is missing the half cock nock on the way down? There could be several reasons but none of them are relevant because the major failure needs to be corrected first. I suspect the sear spring is too weak to push the sear into the half-cock notch as the hammer falls but you need to correct the primary failure of the manual safety before you move onto the secondary problem of the sear missing the half-cock notch.
In the words of Abraham Lincoln, "One war at a time".

Correct the manual safety issue first and then seek out the other failures.
Thanks,,makes sence!!

[Mk42gunner]

And this situation illustrated why we do the full safety and function checks any time anything is changed in the fire control mechanism of any fire arm.

I agree with the safety needing to be refitted or replaced to correct the initial problem by the way.

Robert

[KYCaster]

Did a trigger job on a 1911 today,my 1st attempt ar 1911.came out very nice,crisp and 2lb,10oz pull.all safety checks were tried,and all works well,except....safety on,pull trigger,then switch safety off,and the hammer will drop,right past the halfcock notch.why would this do this,or what have i done?
Btw,,,polished all internals,didnt change any angles,,only real stoning was on the hammer hooks,,took them down to .0018,,,



Did you put an extra zero in there or you really under .002 sear engagement? If that is the case it surely explains your problem.

Jerry

[Greg S]

You need to tig up your safety or install and fit a new one, the sear stop block is short and allowing the sear to move to the peak of your new shorter .018 hammer hooks.

To verify, assemble without the grip safety. Pull the hammer back and engage the safety. Look in the safety and see where the nob on the safety blocks the sear. How much does the sear move when you pull the trigger before it gets stopped by the sear block nob on the thumb safety. If the sear moves at all, it is too much. Build up the nob where the sear hits the thumb safety by tig welding and refit until it just goes into position.

If you don't have access to. Tig welder, buy a new one from Brownells.

Did you replace the steel trigger? Is this a Colt or a series 80 style fp block system.? The potential for the pistol to inertia fire with a steel trigger has been increased with the shortened hammer hooks and reduced trigger and sear spring pressure.

Once you get the safety corrected and it passes a function test, live fire with only two rounds in the mag a dozen times to prove it won't go full auto on you. Better to find out proving it than with a mag full.

PM sent.

[1006]

If you google “cylinder and slide safety check”, you will find the instructions for safety checks performed after installing a new action set. These are sent to buyers of the “Cylinder & Slide” action kits for 1911’s.

They include some information regarding hammer hook dimensions and safety engagement.

It is generally believed that hammer and sear modifications on 1911’s with cast/mim parts can result in the uncovering of an interior flaw in the metal, and the removal of the surface hardness. A trigger job on these type parts is likely to fail-sooner or later.

On my Kimbers, I have always ordered either the Cylinder and Slide (C&S) action kits or the EGW kits. I have also installed the C&S kit in a Caspian, a S&W, and a Colt Delta Elite. All total, six guns over the years, both kits seem to safety check and function perfectly without modification. However, a new safety is required about half of the time.

[AndyC]

Btw,,,polished all internals,didnt change any angles
That's scary right there. Polished what, exactly?

Also, I disagree (to an extent - it depends what you've done) that a simple thumb-safety swap alone will fix this - you may have bolloxed up the sear and hammer-engagement too. In that event, the thumb-safety is simply keeping that (possible) faulty engagement from tripping until you release it, but you may indeed need to replace the thumb-safety too, depending what you messed with.

I overlaid 2 pics from Kuhnhausen and animated them to come up with this::
https://i.imgur.com/LfGYj6S.gif

https://i.imgur.com/qjEAFgI.jpg

The section between the 2 arrows (the red and blue parts) has to be perfectly fit - a few extra file strokes to the red nub will render the safety useless, because that extra distance you've just created will permit the sear (in blue) to move back if the trigger is pressed - and on a 1911, you'll notice it doesn't take much movement there to release the hammer from the sear-nose (the tiny tip of the sear). Hopefully that's all it is and that a thumb-safety swap might be all you need.

[Petrol & Powder]

AndyC, Thank You for the excellent diagrams and animation. That should help the OP understand the situation.

And I particularly enjoyed your very British use of the term "bolloxed" :smile:

[rondog]

That's scary right there. Polished what, exactly?

Also, I disagree (to an extent - it depends what you've done) that a simple thumb-safety swap alone will fix this - you may have bolloxed up the sear and hammer-engagement too. In that event, the thumb-safety is simply keeping that (possible) faulty engagement from tripping until you release it, but you may indeed need to replace the thumb-safety too, depending what you messed with.

I overlaid 2 pics from Kuhnhausen and animated them to come up with this::
https://i.imgur.com/LfGYj6S.gif

https://i.imgur.com/qjEAFgI.jpg

The section between the 2 arrows (the red and blue parts) has to be perfectly fit - a few extra file strokes to the red nub will render the safety useless, because that extra distance you've just created will permit the sear (in blue) to move back if the trigger is pressed - and on a 1911, you'll notice it doesn't take much movement there to release the hammer from the sear-nose (the tiny tip of the sear). Hopefully that's all it is and that a thumb-safety swap might be all you need.

When I put WWII Colt parts in my RIA GI model, I had this same issue with the WWII Colt thumb safety. Took it to my gunsmiff, and he TIG'd a tiny nub right at the spot where both arrows are pointing. Just a TINY nub. Hit it a couple licks with a file, all fixed! Blew my mind.

[Baltimoreed]

I’ll also add another thanks for the animation. A picture is worth a thousand words. And 50.00 worth of parts.

[mainiac]

I have .018 hammer shelf,,dont know where the .002 thing came from.

[mainiac]

You need to tig up your safety or install and fit a new one, the sear stop block is short and allowing the sear to move to the peak of your new shorter .018 hammer hooks.

To verify, assemble without the grip safety. Pull the hammer back and engage the safety. Look in the safety and see where the nob on the safety blocks the sear. How much does the sear move when you pull the trigger before it gets stopped by the sear block nob on the thumb safety. If the sear moves at all, it is too much. Build up the nob where the sear hits the thumb safety by tig welding and refit until it just goes into position.

If you don't have access to. Tig welder, buy a new one from Brownells.

Did you replace the steel trigger? Is this a Colt or a series 80 style fp block system.? The potential for the pistol to inertia fire with a steel trigger has been increased with the shortened hammer hooks and reduced trigger and sear spring pressure.

Once you get the safety corrected and it passes a function test, live fire with only two rounds in the mag a dozen times to prove it won't go full auto on you. Better to find out proving it than with a mag full.

PM sent.
Thanks,for the advice!!
I have to much access to the tig torch im afraid!!!make my living with 1.
Is the ruger safety made of some wild alloy? Or can i use 70 wire,,standard?

[Bigslug]

Some firsthand experience here. . .

What you need to do is perform what Colt calls a "scant safety" function check. Engage the safety and then pull the trigger - hard. Then slowly ease the hammer back and listen closely for a slight "click". That click is the telltale sign of a safety that is over-filed or worn too far. That missing material on the safety allows the sear to rise out of the hammer notch slightly under trigger pressure. The click you hear is the sear falling back into the notch.

My own experience with Ruger - an early-ish one - was that it exhibited scant safety right out of the box, and requesting a new safety from the factory gave me a drop in fit that was ALSO scant safety. I fitted a new safety from another brand and all became right with the world.

[AndyC]

AndyC, Thank You for the excellent diagrams and animation. That should help the OP understand the situation.

And I particularly enjoyed your very British use of the term "bolloxed" :smile:


I’ll also add another thanks for the animation. A picture is worth a thousand words. And 50.00 worth of parts.

Most welcome, chaps ;) I hope they're useful.


How much does the sear move when you pull the trigger before it gets stopped by the sear block nob on the thumb safety. If the sear moves at all, it is too much.
^ This x1,000. The sear can't afford to have any movement - the sear-nose is practically on a razor's edge (particularly when the hammer-hooks have been lowered to .018") and won't take much to fall.

[DougGuy]

Thanks,for the advice!!
I have to much access to the tig torch im afraid!!!make my living with 1.
Is the ruger safety made of some wild alloy? Or can i use 70 wire,,standard?

Er70S works fine. Might want to use a piece of angel hair, or take the smallest wire you have and sand it down really small since you need so little weld metal and you need it to only "sit" on the right hand side of the V notch, not fill the whole notch up.

Heat sink the safety in a vise, get on and get off, let cool, repeat until you have a little buildup on the right hand side of the "V" (if the boss is facing you) then use dremel tool and shape/remove until the safety will snick on and off and zero movement of the sear.

Haha I used a piece of a recoil spring as filler wire to do mine, oh jeez man that is some HARD ****! Took me forever to dremel it back to size.

Edit: Okay found some pics, there are two 1911 safeties here, both made by AO, the one that is filed and has metal dust on it is from a 1911A1 and it is fitted properly, the sear does not move at all. This one is the checkered US military style safety.

The other one, which has a serrated thumb pad is the one that was loose and allowed sear movement. I used a tiny blob of metal from a recoil spring to build up the area that contacts the sear leg. It was filed down, and you can see how much material I added to it because there is a notch that was left in there purposely, I didn't need to fill the entire area with weld, only needed enough to file back down to securely contact the sear and now it has zero movement.

First pic, the tiny one puddle of weld:

276107

Second pic, most of the weld is now dremeled off and the safety fits and works. In this pic, the welded one is the rear one.

276108

Now cleaned up and blued, the notch is still there, it doesn't hurt anything, it represents the surface that was filed from the factory when I received it. I just didn't want to heat the part any more than was minimally necessary and it works fine:

276109

If this was a customer's gun I would have welded the notch up but it is my personal gun so it got what it got and that's that.

[AndyC]

Great pics, Doug :drinks:

Here's a little gif I put together so the OP can see what should happen inside (the grip-safety is removed and the view is from behind and slightly below):

https://i.imgur.com/UIl43Do.gif

You'll notice how tightly the nub of the thumb-safety slides up to brush the flat surface of the rear of the sear.

[mainiac]

You guys are awesome!!
Im gonna tig it,and see.its such an awesome trigger now,,2lb10oz,,,with no slack or creep,,

[mainiac]

Update,,,tig welded the safety, then filed it down,until it would lift...blocks trigger now,,splendidly!! Thanks for the advice!

[AndyC]

Well done! :)

[JimB..]

A 1911 manual safety, when properly fitted, locks the sear AND blocks the hammer when engaged.


I believe that the thumb safety blocks the sear, and if that fails the hammer will fall and you can watch it swipe the thumb safety off as the hammer falls all the way to the firing pin. Hammer does burn off some energy in this process, so may or may not give the firing pin enough push to fire the round.

Give it a try, remove the sear and sear pin, pull the hammer back, engage the safety and let loose the hammer.

[AndyC]

The thumb safety only blocks the movement of the sear, correct.

[DougGuy]

I believe that the thumb safety blocks the sear, and if that fails the hammer will fall and you can watch it swipe the thumb safety off as the hammer falls all the way to the firing pin. Hammer does burn off some energy in this process, so may or may not give the firing pin enough push to fire the round.

Give it a try, remove the sear and sear pin, pull the hammer back, engage the safety and let loose the hammer.

You left out the half cock notch which catches the hammer and prevents it from traveling to the firing pin in this event. I.e. WITH the sear and pin installed as it typically would be.

[JimB..]

You left out the half cock notch which catches the hammer and prevents it from traveling to the firing pin in this event. I.e. WITH the sear and pin installed as it typically would be.
Yes, I did. Was really just pointing out that the hammer is not blocked by the thumb safety, certainly not arguing that the system has a catastrophic single point of failure. That said, once someone starts with just a little polishing it’s hard to predict how things are going to go.

[Scrounge]

When I put WWII Colt parts in my RIA GI model, I had this same issue with the WWII Colt thumb safety. Took it to my gunsmiff, and he TIG'd a tiny nub right at the spot where both arrows are pointing. Just a TINY nub. Hit it a couple licks with a file, all fixed! Blew my mind.

Things like that are why it is sometimes worth spending the money for a specialist. Not that they do anything that you couldn't do, but that they know exactly where to do it, and how much to do.

[AndyC]

Scariest thing in the world to me is when someone installs a thumb-safety on a 1911 and they say "It just dropped in". Eek.