How Do You Prevent Hammer Fall On A 1911?

[AzShooter]

I did a trigger job on my Colt 1911 22. Basically all I did was replace the trigger parts with a kit from Cylinder & Slide. I also replaced the thumb safety. That was the easy part.

I took it to the range today and the hammer followed after every shot. A new round chambered but didn't go off.

I'm at a loss and will take any advice given.

 

[Scorch]

You did a trigger job without knowing how and now you have a problem. The most common causes of hammer follow-down are insufficient sear engagement and insufficient sear spring tension. The three-fingered sear spring is also the trigger return spring, which can be a factor if your trigger return spring is too light. So, long story short, you tried to make the trigger too light without actually doing a trigger job. Increase the sear spring and trigger spring tension and it should go away as long as the sear surfaces are cut properly.

 

[AzShooter]

Thanks. I had watched the YouTube videos on doing the trigger job. I ordered a replacement enhanced kit from Cylinder & Slide which should have been a drop in kit. Yes, it turned out to be the sear spring. Thanks for your help.

 

[4V50 Gary]

Glad it's fixed. Suggest you take a 1911 class at some NRA Summer Gunsmithing School.

 

[44 AMP]

Also be aware that the sear spring might be only a temporary fix. Might last as long as you do, might lose some tension and fail at some point down the road.

My experience with "drop in" kits from aftermarket sources is similar to computer parts during the early days of home PCs. "fully compatible" meant it would probably fit. "100% compatible" meant it would fit and MIGHT work!

I worked on .45s in the Army. ALL the parts were "drop in".
NO fitting was done, generally speaking, if a repair part didn't fit, or fit and failed function test, it was tossed and a different part installed until things worked.

 

[HiBC]

A problem with hammer drop is it could result in shooting someone,perhaps yourself. Pretty high stakes.

Scorch gave you good info. Its tough for inexperienced eyes to see the right things.
Youtube instruction is great stuff. I have learned a lot there. In its own way,a 1911 trigger job is a life and death operation.

Cylinder and Slide makes good stuff. If you did not touch the sear and hammer surfaces,odds are they are more perfect than 90% of the stoned sear surfaces and 100% of the Dremel Buffed sear surfaces.

That said,"Trust but verify" You can't assume anything. I don't know how Youtube would teach you how to check sear angles and engagement. I have a Bausch and Lomb Toolmaker Microscope with a protractor ,reticle,and X-Y stage controlled by big micrometer heads. But most folks don't have those.

You can assemble them on the outside of your frame and look with magnification. The geometry of the notch and sear should show an .018 in minimum depth a sear sngagement. But sear to hammer notch geometry can be,for lack of better term, "uphill" Neutral, or "Downhill"

"Downhill" is not good. A minimal amount of "Uphill" is generally good. It may not be the lightest, but the simple mechanics of the engagement would tend to sustain the sear engagement regardless of the sear spring tension.

Ideally,the sear spring's primary duty is to keep the parts from flopping around. It tells the sear "You belong in the hammer notch at this time"

The sear spring CAN fine tune a little more trigger pull, If the sear engages full cock in the hammer notch,it should hold full cock without the sear spring's help. If it won't,there is a problem.

A typical part of tuning a sear is a VERY LIGHT chamfer with a fine stone on the breaking corner /sharp edge of the sear. The function of this chamfer has to do with sharp edges being fragile and subject to damage. a .002 or so chamfer makes for a stronger "trigger break" edge. Its a mistake to cleverly reduce the effective sear engagement by a larger chamfer,causing the hammer notch to cam the sear out of the way early.

WOW!! All this!! Who knew!!! We just are not born with all of John Moses Browning'd genius. And a few minutes Youtube is not a substitute.

I understand,finding a skilled 1911 Smith is not easy, Every professional trade has its wealth of required knowledge. You would not ordinarily do surgery from a Youtube video,but a 1911 trigger job.well....

Actually,some surgery might be simpler.

The right thing to do? Find a good 1911 Smith.

Approach him/her with " I independently did my own trigger replacement. I recognise my inexperience. May I pay you to check my work to see if its safe. Would you correct any shortcomings? Tell him everything.

Gunsmiths may get a touch crotchety about cleaning up your mess. Generally,they would prefer you asked them if they would install your C+S kit,Then they have no rookie mistakes to undo.

But ultimately, a good 1911 smith first wants your gun to be safe and reliable.

Pay him/her for their time and your peace of mind. A "dang it!! The hammer dropped again!! on a live round can be tragic.

 

[AzShooter]

HiBC:

Good advise.

I've already contacted a gunsmith that is willing to help me. I guess a drop-in kit really wasn't.

It's not that I haven't done upgrades before but this is a (Walther) Colt 1911 22. None of my normal gunsmiths will touch it. They only do brand names.

So, we will see what my friend, a local gunsmith that is retired, can do.

Thanks for all your help.

 

[44 AMP]

I would make a small addition for clarification, there is a different between "hammer drop" and "hammer following" though its not obvious to the naked eye, usually.

Hammer Following is USUALLY not a dangerous condition that results in a cartridge firing, ...USUALLY, though it can.

Hammer following is exactly what it sounds like, the slide pushes the hammer back to the full cock position (or slightly beyond) and then when the slide moves forward, so does the hammer, "following" the slide. This USUALLY does not result in enough energy to fire a round.

"Hammer Drop" is different, the hammer stands at full cock position as the slide closes, but does not stay there, it falls from full cock when the slide shuts. THIS WILL FIRE A ROUND (unless the gun has a firing pin blocked until the trigger is pulled. Standard 1911A1s do not have this feature. Some 1911A1 pattern guns do.)

Incorrect (including insufficient) hammer/sear engagement is the usual cause for both hammer following and hammer drop. With following, the engagement is not enough to hold the hammer back, at all, with hammer drop, it is enough to hold the hammer back until it is "jarred off" by the slide closing or some other reason.

Both look the same to the eye, the slide shuts and the hammer is down. You might notice the slide shut and then the hammer fall, you might not. Careful testing with an empty gun and with proper dummy rounds (NOT snap caps) should tell you the difference.

Good luck.

 

[WmMunny]

New guy's opinion: remove the "trigger job" parts, replace them with the ones that were in there before you started messing with your gun. If the parts vendor will take them back, send them. If not, just eat the cost and consider it a cheap enough lesson.

 

[AzShooter]

I put all the OEM parts back in and everything runs fine. I ran another 200 rounds of Blazers and all functioned perfectly.

Trigger pull is a bit heavy so I ordered some new lighter sear springs. I'm going to try that first.

I always keep the stock parts just in case. Good thing I do this for fun. It's a great learning experience for me.

 

[Unclenick]

It took me going through three sears and two hammers to learn trigger work, and that was with tutelage. Even then, I wound up designing my own fixtures for the hammer and sear, since I knew I wasn't going to be doing this day in and day out to keep the feel of things. While 0.018" of hammer hook is a fine lower limit for target guns (just remember to be pointing downrange and holding the trigger back to keep the disconnector up when you release the slide to load the gun; this prevents hammer drop), the late Russ Carniak recommended I stick with 0.025" engagement on combat guns and use an adequate amount of rollover relief on the back edge of the sear to prevent sear bounce. That still makes a perfectly crisp 4 lb combat trigger if you have full contact between the hammer hook and sear nose, and the small amount of extra overtravel is not something I've ever been sensitive to.

On my combat 1911's, my test is to lock the slide back, balance the gun with the muzzle pointing up and left while pinching the frame over the mainspring housing retaining pin at the bottom rear corner of the grip frame between the thumb and index finger of my right hand. I then use my left hand to release the slide with as little contact as possible. If the hammer doesn't follow or fall with the gun free to move that much, I am confident that I am good to go, safety-wise.

 

[AzShooter]

I put the C&S trigger kit back in today. I also replaced the OEM sear spring with a C&S. I wish it would have come with the kit but I had to buy it separately.

Works like a charm. With no gunsmithing, just replacing the parts in the kit and the springs I now have a 3.5 pound reliable trigger. It was advertised to get a 4 - 4.5 pound kit but I guess the spring made the difference.

 

[Bill DeShivs]

"How Do You Prevent Hammer Fall On A 1911?"

Leave it alone.

 

[Scorch]

Leave it alone.

Starting to sound like me!

 

[Nathan]

I ordered a replacement enhanced kit from Cylinder & Slide which should have been a drop in kit.

This is the problem. There are no true drop in 1911 parts. As genius as John Browning was, his drawings represent parts which require final fitting as far as I can tell. Modern 1911’s are base on that dwg set, but all have their own dwgs, different processes, different part quality….

A perfect hammer/sear by someone’s std is 90 deg…or neutral angle. Meaning in a pistol set in a jig, fully sprung, the hammer does not move as the sear is released.

Positive engagement actually slightly cocks the hammer when pulled. Like a CZ75.

Negative engagement slightly lowers the hammer as the trigger is pulled.

Simply stated, You really want a very slightly positive engagement so the hammer and sear return to full engagement when released. This is only really understandable as an assembly. You also want 0.018 - 0.025” hammer hooks. I read the cool kids run 0.012”, but I like my fingers and toes!

 

[Jim Watson]

As genius as John Browning was, his drawings represent parts which require final fitting as far as I can tell. Modern 1911’s are base on that dwg set, but all have their own dwgs, different processes, different part quality….

I think part of Mr Browning's design (and Colt's tooling) genius was that they were making military weapons and did not have time to fiddle around hand fitting. Take apart a pristine USGI or old GM and look for file and stone marks. I doubt you will find any.

I doubt Colt and Armscor et al are doing any "fitting" now. It is just the higher end stuff that is built to what used to be target pistol fit and/or mutated by somebody who thinks he is smarter than Mr Browning that has to be "fitted." Along with aftermarket parts that have to be made adaptable to all those people's funny notions.

 

[44 AMP]

This is the problem. There are no true drop in 1911 parts.

There haven't been any 1911 parts since the military adopted the 1911A1. SOP for military Small Arms Repair has been to maintain 1911s with 1911A1 parts as needed, ever since then.