1911 firing to half cock...need some help

[AllenM]

Maybe like try increasing disconnector tension. Or try another disconnector.
I set tension by removing hammer and sear. And just installing the disconnector, sear spring and MSH.
then using a trigger pull gauge set the disconnector leaf to at least 8oz thats the minimum I set mine. Hard to believe you would be below that though. 8oz functions reliable. but it is for a light trigger pull. 12 oz is a good rating.
After everything you've provided chances are you were right in the first place that the problem may lie with the disconnector. Trustingly hammer and sear are cut correct, which you seem to know what your doing. I think I would pull the disconnector out of the other gun and try it if you don't have another one. At least that would let you know if your right.
I have run across a gun with the sear and hammer pin holes out of spec which was a nightmare to get a decent trigger. But with Caspian I doubt that is the case.

 

[wolfman]

For what it is worth, if the barrel link was to long, would it cause the slide and barrel to lock up just short of the slide being fully forward?

 

[baba]

I will try the disconnector switch tomorrow or Saturday. Hopefully that does the trick. I have given up the hunt for my headspace gauge...so I will have to order a new one and will order a 20lb recoil spring at that time too. Just in case. I will report back what I find. I do believe my hammer and sear are properly fit as it passes all the safety checks, and they look find when I put them on top of frame to check their geometry. To make that last part clearer, I pin them to the outside of the frame so I see how they are working together and they look OK.

Wolfman...if the barrel link were too long I would think I'd see 100% lug engagement (which I'm at about 80%), and since this barrel had a pre-cut bottom lug I would also probably see poor or no contact between the slide stop pin and bottom barrel lugs. May also see the rear of the bottom barrel lugs crashing in to the frame bed, but I have checked for contact there and don't have any.


Thanks guys, hopefully we are close to the bottom of this.
-Brian

 

[ghitch75]

what will the 20lb spring do?.......16lb is all you need if everything else is setup right......are you shooting +++P ammo?......i think it will cause more trouble than help.......as said your hood/head space is to tight.....even a out of spec disconector would let it go into battery every time....

 

[baba]

hm...I'll have to think about your statement on the disconnector. What I see compared to the other 1911 I looked at (which apparently has a shorter disconnector) is that it will either fire, or not fire, but does not fall to half cock if I pull the slide back a tiny bit. This is consistent with the behavior of AllenM's pistol that he tested. I believe that could be due to my disconnector being too long and prematurely engaging the slot in the slide.

I do still plan to check the headspace.

-Brian

 

[baba]

Oh, and I was thinking the 20lb spring would be helpful to get it in battery if everything is still tight. It costs $5, is easy to try and if I'm already ordering something else I don't have to pay shipping just for a $5 part.

Brian

 

[walt o]

this might be some help
The reason the hammer follows when the slide goes into battery is the sear never fully engages the hammer hooks because the distance between the pins is too long. The sear is simply too far away from the hammer. The only way to correct this problem is to find a sear with a long “nose”, the dimension from the center of the pin hole to the sear face. Try to maintain that dimension, don’t over stone the sear face and keep it as long as possible; it should do the trick. These frames are always a real problem and you usually put far more time and effort into them than they are ever worth. Click Here to view 'bt002005.pdf'.

 

[baba]

That isn't the problem I'm having walt. I have proper sear engagement and disconnector engagement. The hammer only falls halfway when the trigger is pulled and the slide is ever so slightly rearward of its full forward position. The hammer resets properly every time the action is cycled.

I didnt have any time this weekend to swap the disconnectors. I will attempt to get to that this week.

 

[walt o]

Try removing the grip safety,and cycling the gun .that way you can look at the fire controll parts and maybe see what is happening. I have tried to make this happen on several of my 1911's and and can't make hammer fall to the 1/2 position .Only possibility i see is the disconnect slipping off the sear. It is probably a small glitch that we are all overlooking .Other suggestion ask for help on the 1911 forum -LOGMAN or C.W.WARNER, PISTOL WRENCH can help

 

[baba]

Thanks again Walt. This thread has grown quite a bit. I have done just as you suggest. What is happening is that the disconnector is engaging the sear, then slipping off about half way through the cycle (again, only when the slide is held back that tiny bit). I can't make this happen on the other 1911 I have either.

In the mean time, I swapped disconnectors with the other 1911. The disconnector from my gun cycles fine in that one - can't make it do the halfcock thing. The one from the other 1911 is much harder to get to do the half cock thing in my gun, but I can get it to happen. The slide has to be slightly farther back and I can't make it happen as reliably as it I can with the other one.

I measured both disconnectors. The one from mine was 1.309 OAL vs. 1.299 from the other gun. Notice that 1.309 is out of spec by .007. When I measured this before I must have missed it. I do have some kind of number dyslexia which is why I have to triple check everything, but occasionally it does get the best of me. I think the slightly shallower relief in the slide plus the slightly too long disconnector is coming together to get me here. I may order a new disconnector to have a good one on hand, then shorten the current one to spec and see if that fixes the problem.

I wanted to ask another question - I think I read above that the hood clearance to the slide should be .002". Is that correct? I can't quite get a .0015 gauge through there, leaving me to think that the hood may actually be contacting the breechface and not just rubbing it as it swings through. Think I should shorten the hood to get .002 clearance? Can't find a speck in the Kuhnhausen book. I'm sure its in there somewhere though. The instructions I bought with the barrel just said to leave it as long as possible but still allowing the barrel to cam up high enough to get proper lug engagement. Which I do have.

-Brian

 

[IndyGunworks]

well you think you have found your issue with the disconector, so I wouldn't change a thing until you shoot it some more. I do believe you have another issue going on that's preventing the slide from going all the way into battery, but lets try and fix one problem at a time. do your work to the disconector and prove to yourself that its a good fix. THEN concentrate on the slide. It sounds though like the hood could be the source of the problem.

 

[walt o]

If i get your last post correct you are still having a problem with the disconnected from another gun when it is installed in your build and the disc.from your build functions correctly in another gun ? If that is correct best check the dis connecter cutout in the slide .
The common understanding mistake about the hood fit is how much there is fully assembled, often there isn't any, because the recoil spring forces the slide forward, and because the upper slide lug recesses are about .020" larger than the barrel lugs. However, when it is shot the barrel is held forward, and the slide pushed back, all clearance will then open up. This affects accuracy as the slide closes up the upper lug clearance.

To understand how much clearance a given barrel and slide have, retract the slide and insert progressively thicker feeler gauges until the slide will not return to battery. What ever that is, is how much gap between the hood and breech face there is.

 

[ChrisK]

Great description of measuring hood clearance Walt. Disconnector dimensions are measured in three places but for ease of measurement the overall length should be 1.302 +.000 -.009 . If you get your disconnector length correct and hood clearance correct you should be good.

 

[baba]

Ordered the parts, should have them Monday.

On the barrel hood fitting, I want to make sure I'm clear. By 'return to battery' do you mean that the slide is far enough forward for the disconnector to engage and allow the gun to fire?

-Brian

 

[ghitch75]

return to battery is slide forward,flush with rear of frame and barrel full engaged to the locking lugs....i still think your trouble is the hood/chamber not going into battery and hanging the disco....

 

[baba]

Maybe its just late, or maybe I'm thick on this issue...

A given slide and a given frame may not match up at the rear when the gun is fully assembled. For this reason one of the finishing steps is to file/dress this area to get a nice even fit. I don't feel like I can use 'slide flush with frame' as a measurement for fully in battery because of that.

I'll have a new headspace gauge as soon as UPS delivers it (monday I guess). But I want to make sure I'm clear on how to check the hood size issue. That way once I get the disconnector issue figured out I can start working on that, if it is an issue.

And I did measure my disconnector in all 3 segments. The bottom two measurements are in, and the top one is the one that is over. It throws the OAL out as well.

 

[walt o]

You are correct . The rear of the slide can be forward or back of the frame . Being in battery is a general term . uSUALLY = LOADED AND SAFE TO FIRE ,note safety's can be engaged or not, Breach in proper,

 

[ghitch75]

isn't this a finished piece?...i know there a long ...but if the barrel wasn't fitted right and lower lugs to thick/hood to tight your slide will hang over....

 

[baba]

It is not a factory gun. I hand fit a Kart Easy Fit barrel to a caspian slide and frame. I followed his instructions and believe I have it right, but am looking for a way to double check. So the rear has never been dressed to mate. It is possible that the hood is still too long, but I have good top lug engagement and even engagement on the bottom lugs. I have almost no pad left at the top of the barrel I just can't check the hood length using the match up of the slide and frame...am trying to figure out another way. I guess I could test where the firing pin is hitting the primer pocket. It should be at centerline or below.

Is it necessary for the slide lugs to contact the front or the back of the barrel top lugs? I most ordnance drawings it does not appear they do. I could try marking those areas and see what I have.

-Brian

 

[ghitch75]

i didn't mean factory......i mean you where done fitting it?.....i like them to rest on the back of the slide lugs.....dykem would tell you a lot....