Trigger pin waking

Fyrhazzrd · #1 05-01-10, 17:46

I seem to be having this problem with my Lower. I don't want to name manufacturers, because I'm not sure it's a manufacturing issue.

What is happening, that I notice is that after I fire off 40-50 rounds and then mid magazine I can't squeeze the trigger. It acts like it is on safe. So I look at it and the pin that holds the trigger assembly in place is sticking out by about a 1/4". I then clear the weapon and separate the upper from the lower. And push the pin back in. I am easily able to move the pin in and out with my thumb. Another thing I noticed is that there is quite a bit of oil seepage around this pin. It did this twice today only firing 80 rounds.

Once I got home I cleaned my weapon and disassembled the lower receiver and wiped everything dry. It seemed to be a little oily. I put it back together and I can still push the pin in and out with my thumb without any difficulties at all.

Is this a common problem? Is it possible that I may have the wrong size trigger pin? Or do you think there may be a tolerance issue with my lower?

If this is a common issue, are there any suggestions out there to fix the problem?

Edit: oh crap, I apparently checked my spell checker at the door.. I meant walking in the title and not waking. LOL

Quib · #2 05-01-10, 19:24

The hammer spring rides on top of the trigger pin. It sits in the groove cut in one side of the trigger pins circumference. This is the only security the trigger pin has against walking.

If your trigger pin is walking, check the position of the hammer spring tails. If they are sitting correctly, then the groove in the trigger pin may need to be opened up a bit.

Peanut · #3 05-01-10, 19:49

Quote:

Originally Posted by Quib

The hammer spring rides on top of the trigger pin. It sits in the groove cut in one side of the trigger pins circumference. This is the only security the trigger pin has against walking.

If your trigger pin is walking, check the position of the hammer spring tails. If they are sitting correctly, then the groove in the trigger pin may need to be opened up a bit.

Also check to make sure that the hammer spring is attached to the hammer correctly as depicted in the diagram.

If the hammer spring doesn't rotate under the hammer pin, the spring doesn't contact the trigger pin properly and will walk out on you. An indicator that this has occurred, is a light trigger pull on a standard FCG

Quib · #4 05-01-10, 19:58

Yep, another good point.

If the hammer spring is not installed correctly on the hammer, with the spring coils in the correct direction, then the spring tension is lacking.

This could also be a cause of trigger pin walking.

Fyrhazzrd · #5 05-01-10, 20:22

Quote:

Originally Posted by Quib

Yep, another good point.

If the hammer spring is not installed correctly on the hammer, with the spring coils in the correct direction, then the spring tension is lacking.

This could also be a cause of trigger pin walking.

Wow, thanks that was it. The hammer spring was upside down. I even tore the thing down twice and didn't notice that.

Edit: I will test it at the range next weekend as long as it doesn't rain. It seems like the weather is beautiful all week and rain every weekend.

Quib · #6 05-01-10, 21:11

Quote:

Originally Posted by Fyrhazzrd

Wow, thanks that was it. The hammer spring was upside down. I even tore the thing down twice and didn't notice that.

The credit and thanks all go to Peanut.

He’s the one that took my corrective action and went just one step further. And it will be that one step that hopefully will correct your pesky trigger pin problem.

Fyrhazzrd · #7 05-01-10, 23:57

Quote:

Originally Posted by Quib

The credit and thanks all go to Peanut.

He’s the one that took my corrective action and went just one step further. And it will be that one step that hopefully will correct your pesky trigger pin problem.

ha ha.. yeah, I accidentally hit quote instead of reply. But yes many thanks to everyone for the help. I totally missed that one. Although I kind of liked the light trigger pull better..

Peanut · #8 05-02-10, 18:21

It was a collective effort. I have seen trigger and hammer pins that were cut a little shallow. Most of the time it's improper assembly.
I have done it myself. Thats why I visually inspect, then function check. If the trigger feels sweet, then I know I messed up.

HA HA HA

I'm glad I could help.

sdacbob · #9 05-02-10, 18:42

Quote:

Originally Posted by Fyrhazzrd

Wow, thanks that was it. The hammer spring was upside down. I even tore the thing down twice and didn't notice that.

Edit: I will test it at the range next weekend as long as it doesn't rain. It seems like the weather is beautiful all week and rain every weekend.

Been there, done that. I installed the heavy hammer spring upside down on my S&W Mp15R. The pin was walking on that and wouldn't fire the 5.45 Russian ammo, but when I switched to my 5.56 upper it worked just fine. Made 3 wasted and frustrating trips to the range before I got it corrected.

Quib · #10 05-02-10, 20:44

Quote:

Originally Posted by Peanut

It was a collective effort.

....