AR trigger pin - problem

mjes92 · February 25, 2013, 03:04 PM

I've been Having trouble with my trigger pin partially walking out of my carbine lower after 10-20 shots from the bench target shooting. To the point of the trigger not functioning. This has never been an issue before.

Does the pin need to be in a specific orientation? I don’t think so.

I’m guessing the detent grooves may be too shallow.

Any suggestions?

Dfariswheel · February 25, 2013, 08:05 PM

Check the pin to be sure it's not bent or broken.
Make sure both the legs of the hammer spring are on top of the trigger pin.

If all that's good, consider just replacing the pin. They're not expensive.

Final option is to use a small file to slightly deepen the groove in the pin.
You can use the very tip of a small round needle file, or the edge of a standard American triangle file. The standard American triangle file is not sharp and will do a nice groove.

AR15barrels · February 25, 2013, 09:56 PM

There are many causes for this problem.
The pins themselves are rarely the cause though.
First, is the hammer spring installed correctly?
If the hammer spring is installed backwards on the hammer, the legs of the hammer spring will not lay alongside the trigger correctly into the trigger pin groove.

Next, is the trigger keeping the hammer spring from getting into the trigger pin groove?
Some of the hammer castings are sloppy and need a little correction with a grinding wheel or cutoff wheel.
The hammer spring leg should lay freely into the trigger pin groove throughout the full trigger travel.
If you hold the hammer back and look down into the fire control pocket while finger ufcking the trigger, you should not see the hammer spring leg moving up and down as the trigger is articulated through it's full range of travel.

mulespurs · February 26, 2013, 07:52 AM

I think that the answer to your problem may be very simple. My ar-15 had exactly the same problem that you describe. The problem may be the j-spring in the hammer pivot hole. It is not listed seperately anywhere that I have found.

This spring is only maybe 1/2 inch long, J shaped and should protrude into the hammer pivot hole. supposedly this spring is rivited in the hammer and should not fall out during dissasembly.
Mine did and caused quite a headache.
I pulled one out of another hammer, installed it and problem solved.
Try a different hammer if nothing else. Let me know if this works.
Later.

mjes92 · February 26, 2013, 05:37 PM

I'll check it out.
I knew I went to the right place.

Thanks Guys

AR15barrels · February 27, 2013, 04:18 AM

Quote:

Originally Posted by mulespurs

I think that the answer to your problem may be very simple. My ar-15 had exactly the same problem that you describe. The problem may be the j-spring in the hammer pivot hole. It is not listed seperately anywhere that I have found.

The OP has a problem with trigger pin walk.
You are describing the solution for hammer pin walk.
The j spring has nothing to do with retaining the trigger pin.

mjes92 · February 28, 2013, 11:14 PM

I believe improperly installed hammer spring was the problem.
Just as AR15barrels described.

Thanks

February 25, 2013, 03:04 PM	#1
mjes92 Senior Member Join Date: January 28, 2013 Location: Land of 10,000 taxes Posts: 211	AR trigger pin - problem I've been Having trouble with my trigger pin partially walking out of my carbine lower after 10-20 shots from the bench target shooting. To the point of the trigger not functioning. This has never been an issue before. Does the pin need to be in a specific orientation? I don’t think so. I’m guessing the detent grooves may be too shallow. Any suggestions?

February 26, 2013, 07:52 AM	#4
mulespurs Senior Member Join Date: February 26, 2012 Posts: 115	Check this while you are at it I think that the answer to your problem may be very simple. My ar-15 had exactly the same problem that you describe. The problem may be the j-spring in the hammer pivot hole. It is not listed seperately anywhere that I have found. This spring is only maybe 1/2 inch long, J shaped and should protrude into the hammer pivot hole. supposedly this spring is rivited in the hammer and should not fall out during dissasembly. Mine did and caused quite a headache. I pulled one out of another hammer, installed it and problem solved. Try a different hammer if nothing else. Let me know if this works. Later.

February 26, 2013, 05:37 PM	#5
mjes92 Senior Member Join Date: January 28, 2013 Location: Land of 10,000 taxes Posts: 211	I'll check it out. I knew I went to the right place. Thanks Guys __________________ Dad !!! "It's only going to be perfect if you do it yourself." - my teenage daughter Dad !!! "I'm not scared" My Cancer fighting daughter." Cancer Sucks NRA - Life Member

February 28, 2013, 11:14 PM	#7
mjes92 Senior Member Join Date: January 28, 2013 Location: Land of 10,000 taxes Posts: 211	I believe improperly installed hammer spring was the problem. Just as AR15barrels described. Thanks __________________ Dad !!! "It's only going to be perfect if you do it yourself." - my teenage daughter Dad !!! "I'm not scared" My Cancer fighting daughter." Cancer Sucks NRA - Life Member

February 25, 2013, 08:05 PM	#2
Dfariswheel Senior Member Join Date: May 4, 2001 Posts: 7,478	Check the pin to be sure it's not bent or broken. Make sure both the legs of the hammer spring are on top of the trigger pin. If all that's good, consider just replacing the pin. They're not expensive. Final option is to use a small file to slightly deepen the groove in the pin. You can use the very tip of a small round needle file, or the edge of a standard American triangle file. The standard American triangle file is not sharp and will do a nice groove.

February 25, 2013, 09:56 PM	#3
AR15barrels Member Join Date: August 23, 2006 Location: Los Angeles, CA Posts: 53	There are many causes for this problem. The pins themselves are rarely the cause though. First, is the hammer spring installed correctly? If the hammer spring is installed backwards on the hammer, the legs of the hammer spring will not lay alongside the trigger correctly into the trigger pin groove. Next, is the trigger keeping the hammer spring from getting into the trigger pin groove? Some of the hammer castings are sloppy and need a little correction with a grinding wheel or cutoff wheel. The hammer spring leg should lay freely into the trigger pin groove throughout the full trigger travel. If you hold the hammer back and look down into the fire control pocket while finger ufcking the trigger, you should not see the hammer spring leg moving up and down as the trigger is articulated through it's full range of travel.