1911 firing to half cock...need some help

[baba]

I had under taken a project to build my own 1911. It came together great and shoots really straight. I am having one problem though. At the range, the gun will occasionally fire to half cock. Sometimes once per trip, sometimes 10 times in 50 rounds. What I have noticed happening is that the slide is not going quite all the way forward. It is still quite tight and has maybe 500 rounds through it. Having finally noticed this at the range, I was able to recreate the problem at home. WHen hand cycling it doesn't seem to occur at all. But if I pull the slide back just a hare...the thickness of a few sheets of paper, it seems the disconnector is depressed just enough that it slides off the sear and the hammer drops to half cock. Push it forward that hair's width, and it fires fine.

So I have three thoughts in my head about how to fix this.

1) shorten the disconnector. It is on the long side of spec, but in spec. I'm hesitant to do this b/c most of the wisdom I have read is that you never shorten the disconnector.
2) Scrape out the slot in the slide for the disconnector, allowing it to seat more deeply. I have never done this on this build and I know this is an area that can be addressed to make things work more smoothly. Should I?
3) Put in a heavier recoil spring. Not sure what I have in there right now, but it isn't very light, or very heavy. I'm thinking it could give me the extra push I need to get the action home when cycling rounds. This fix is also reversible if it doesn't work. Assuming it can still cycle reliably it might be the best option.

Please help me think through this. Could be I'm on the wrong trail, but I have checked many others. The lockwork and safety mechanisms all work properly, which is what leads me to believe it is this battery issue. I just wonder if there is some other fit I should check to see if it is interfering with the return to battery?

-Brian

 

[M67]

When you say you built it, was it a kit, or just parts from various makes that you used?

Is the slide smooth in operation? Is reassembly easy or does the guide rod get bound easy? What type of guide rod did you use? Did you fit the sear to the hammer or just throw them in there? What frame did you use and is the sear pin hole drilled properly?

Just floating and thinking of ideas

 

[baba]

Custom build. Caspian Frame and slide. I would assume they are drilled in the correct spots. Sear and Hammer are Ed Brown, but not a 'kit'. They were fitted using the jig from Brownells and are all within specs. The guide rod is a standard plug type (not full length). The slide moves freely and has very little play on the rails. It passes all safety checks. Hope that helps.

It is not a sear/hammer fit issue - at least I don't think so - because an undersized sear would cause the hammer to return to half-cock after the slide cycled. I have seen that before and this is not what is happening. When the trigger is pulled and the slide is back just that paper's width, it falls to half-cock, not the firing position.

Brian

 

[redwingshooter]

Brian, what recoil spring are you using? Do you know what the poundage is on it? Also what type of ammo are you shooting at the range? Factory or reloads?

 

[midget]

Is the hammer being fully reset and falling to half cock? Or is the slide not completely resetting the hammer?
If it is falling to half cock, it is a problem with the tension on your disconnector from the main spring. Bend the leg that contacts the disconnector to add pressure.
If the hammer is not fully resetting, your slide is not going fully to the rear and you either have too long or too strong of recoil spring. Or something on the slide is binding.

Edit, after re-reading your post, it is likely a combination of the spring tension and that the trigger bar is not sitting far enough forward. If you have an adjustable pre-travel, add some pre-travel back in.

 

[baba]

The hammer is fully cocked by the action. It only falls to half clock when the trigger is pulled, and then only when the slide is back just that tiny bit. The slide is tight but moves freely so I do not believe rearward travel is the issue.

I will have to check the trigger travel but it is moving far enough forward to allow the action to properly reset. May be that it is still not quite right though and I haven't checked that.

The recoil spring weight eludes me right now. Hopefully I still have the parts bag for it....what the heck did I buy? The one part I can't remember....

Thanks and keep the ideas coming!

Brian

 

[partyboy6686]

Wish you were closer to Indianapolis. I would let you try out a variety of recoil springs to see if the fixes your problem. You might PM INGO member AllenM and see if he can help you figure out what the problem is. He is the go to guy for 1911's.

 

[halfmileharry]

What kind of lube are you using between frame and slide? Have you field stripped and put a bare slide on the frame to check for any binding? I built a rat '11 and had that same issue and it was just a bad fit between slide and frame. I cleaned up the frame and slide rails with crocus cloth and used some fishing reel silicone grease to finish breaking in. No problems after that. Just "battery issue"

 

[AllenM]

Does the trigger have an over travel screw? It is possible this has worked its way in some and not allowing the sear to clear the second hammer notch everytime

 

[IndyGunworks]

grip safety might have a "bevel" that sometimes it lets the trigger back all the way, and sometimes if not FULLY engaged it allows the hammer to drop, but not push the sear far enough.

 

[VinceU1]

Check what AllenM and IndyGunWorks said and then if that's not the problem check the tab on the thumbsafety where it engages the sear. It's possible that that part isn't relieved enough to let the sear move far enough to miss the half-cock notch.

 

[baba]

Thanks guys. I will check these things, probably tomorrow, and report back. I've been over some of it a number of times but I can check it all again.

BTW, The recoil spring is an 18lbs from Wolf. That is the standard weight for a 45cal commander.

When I fit the slide to the frame, I used a fine file until it would travel all the way on the frame. I then lapped it with a mix of rouge and oil until it would slide on and off with gravity alone. So I don't think it is that causing the lack of return to battery. What else could it be? I'm working through in my head if the barrel hood could be a hare too long, or if something else in the lock work needs to be investigated to figure it out? Just in case the methods below don't find the issue...

-Brian

 

[wolfman]

Interesting how most of the solutions missed that the problem was caused by the slide not being fully in battery when the trigger was pulled, which is resulting in the hammer only falling to the half cock position, instead of striking the firing pin and setting off the round. I am no smith, but I would put my effort into figuring what is keeping the slide from going fully into battery after each shot is fired.

 

[baba]

Just to be clear, it is 'in battery' as far as being fully locked and safe to fire. The safety will engage, etc. I will check the engagement of the fire control parts again just to be sure, but I think it will ultimately come down to what is keeping that slide from going forward that extra 1/32nd of an inch or so.

That said, it could still come down to the disconnector slot not being deep enough, or binding the disconnector on the frame or something. I never contoured the back of the slide to match the frame, so it could be that it is sitting fine and the disconnector is still pushed a hare too low.





-Brian

 

[IndyGunworks]

Did you fit the upper lugs of this barrel yourself? Did you fit the hood of the barrel yourself? Did you chamber the barrel yourself? Did you fit the lower lugs/link yourself? any one of those could also be a culprit for hanging up some of the time and not going the rest of the way into battery. Dychem would be your friend to see if any of those are having unusual contact issues creating this problem.

 

[ghitch75]

are you shooting reloads or factory ammo?

 

[baba]

The barrel is a Kart EZ fit type. The bottom lugs were precut and the link was there from the factory. The hood was shortened by me to fit. The chamber was pre-cut. This barrel fits by the user filing down two lugs in between the normal barrel locking lugs to the point where the bottom lug raises high enough to sit on the take down pin, AND there is at least the minimum amount of lug engagement on the lugs in the slide.

I shoot mainly reloads. Its a recipe I have used for the past 8 years or so and which works fine in all of my other guns. It is close to most factory loads, if maybe a bit lighter. To eliminate that problem I have tried factory ammo, and the problem presents itself at about the same rate.

-Brian

 

[ghitch75]

i bet your Kart barrel has a tight chamber.....i have fit 20 of them and 15 of them needed the chamber reamed...

will it pass the drop-in test?

 

[baba]

Tight diameter, or tight length of chamber? What is the best way to check for either of those things? Go Gauge?

-Brian

 

[ghitch75]

is the head space good?....top of the hood or just below?....length....go gauge will tell you a lot...