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Langdon TJIB: Hammer dropping

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https://sigforum.com/eve/forums/a/tpc/f/430601935/m/8060080064

August 19, 2019, 08:54 AM
Expert308
Langdon TJIB: Hammer dropping
I have an M9A1 that I picked up used last year. A friend of mine just installed both a TJIB and the G conversion kit for me, and I went and shot it yesterday. The G model part works fine, but about 30% of the time the hammer will follow the slide down as it cycles, reverting the pistol to DA mode. This happens mid-magazine. It does NOT double or go full auto. Has anybody seen this happen? The gun was never shot very much, probably less than a thousand round through it total.
August 19, 2019, 09:41 AM
copaup
Check the sear spring to see if it's installed backwards...
August 19, 2019, 10:24 AM
darthfuster
I had this problem on a 1911 I worked on once. When I went back into it I saw that the sear spring had not seated into position properly. Check that.



You’re a lying dog-faced pony soldier
August 19, 2019, 10:42 AM
Batty67
Interesting. I installed a Langdon TJIB on my 1994 92FS Centurion with some difficulty but it works like a charm. I had trigger follow on my 1989 BHP which had a crisp trigger. Too crisp, as I had to pay a local gunsmith to fix a spring and reassemble the trigger properly. Good luck.
August 19, 2019, 10:57 AM
darthfuster
quote:
Originally posted by Batty67:
Interesting. I installed a Langdon TJIB on my 1994 92FS Centurion with some difficulty but it works like a charm. I had trigger follow on my 1989 BHP which had a crisp trigger. Too crisp, as I had to pay a local gunsmith to fix a spring and reassemble the trigger properly. Good luck.


Thread drift alert: BHP install was a bear for me at first. I did a mag safety delete and when re-installing the whole trigger assembly I learned I needed four Asians sized hands rather than my sausage fingers. Eventually figured out how to install the trigger lever and trigger assembly together. Now it's a piece of cake.



You’re a lying dog-faced pony soldier
August 19, 2019, 12:01 PM
Batty67
quote:
Originally posted by darthfuster:
Thread drift alert: BHP install was a bear for me at first. I did a mag safety delete and when re-installing the whole trigger assembly I learned I needed four Asians sized hands rather than my sausage fingers. Eventually figured out how to install the trigger lever and trigger assembly together. Now it's a piece of cake.


That's why I paid a pro for my BHP. I did the TJIB myself because it looked reasonably straight-forward, and it was, with a crap-load of YouTube videos.
August 21, 2019, 09:06 AM
Expert308
quote:
Originally posted by copaup:
Check the sear spring to see if it's installed backwards...

Well guess what? It was. We're going out after work this afternoon to shoot it again and verify the fix.
August 21, 2019, 10:47 PM
copaup
I’m either psychic or experienced...

I can almost guarantee flipping that spring fixed the problem. Much profanity was used over that spring on my 92.
August 22, 2019, 08:09 AM
pedropcola
Lol. The hint for if the sear spring is installed backwards is if it went in easy. If it was a bit of a 3 handed Bear you done it right.
August 22, 2019, 08:36 AM
Expert308
quote:
Originally posted by copaup:
I’m either psychic or experienced...

I can almost guarantee flipping that spring fixed the problem. Much profanity was used over that spring on my 92.

Test firing confirmed it. It's working link a champ now, thanks.

ETA: FYI for anybody curious, I ordered the TJIB kit with the 12# spring, and I'm getting all the primer strike one could want. Didn't have time last night but I'm eager to put the thing on my trigger pull gauge and see what it measures.
August 22, 2019, 09:51 AM
Rustpot
quote:
Originally posted by pedropcola:
Lol. The hint for if the sear spring is installed backwards is if it went in easy. If it was a bit of a 3 handed Bear you done it right.


I don't remember it being that difficult. There was a pretty good install video I followed and the whole swap took 15 minutes.

Now I'm paranoid that my spring is in backwards. But I've got a few hundred rounds through mine after the TJIAB swap without issue.

I think I went with the 13# spring after some conversations online and with Langdon's support email.
August 22, 2019, 12:27 PM
pedropcola
If it’s working you probably did it right. I have put together 92’s a couple dozen times. Occasionally the spring install went easy. Usually not. It has to be tensioned and the holes lined up in an area that you can’t really access. A 92 total breakdown is almost Glock simple. Except that spring, at least for me.

The ease of complete breakdown is one of my reasons I love 92’s. No easier metal gun to fully take down.
August 22, 2019, 05:28 PM
PGT
I did #11 springs on mine and ignition has been flawless. It's nice having a 2lb SA trigger for fast follow-ups.

I did have some issues with getting the hammer to drop in DA as there wasn't enough travel. Talking to LTT, stoning the top edge of the rear and it's now reliable. It wasn't the kit itself, but rather the frame I put it in...tolerance stacking at work. I swapped the TJIAB kit from another frame and it did the same but was flawless in the frame I pulled it from.
August 23, 2019, 12:04 AM
RioGrande481
I have done two Langdon TJIAB installs. They were not that hard, as long as you have the suggested small crochet hook for a tool.

I have installed #12 hammer springs in mine. I am glad to know the #11 works flawlessly.

I still have to test my latest install, an Inox Brigadier 92FS.


RioGrande481

“I didn’t get where I am today by everything smelling of Bolivian Unicyclist’s jock straps!”
C.J. Supercut 1976