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Posted: 8/18/2012 1:45:49 AM EDT
| The past 3 rifles I have built, all with good quality lower parts kits and lower recievers, have been having the trigger pins walking out on them during firing. Has this been happening to anyone else? And just to be sure you know I am a Colt armorer and I have checked and recheked the rifles and the springs are in correctly. |
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Found this in the trouble shooting sub forum.
http://www.ar15.com/forums/t_3_66/241858_New_Trigger_and_hammer_pins_walking_out__Why_my_rifle_is_not_igniting_the_primer_.html |
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I can understand the possibility of one lower having an issue. But an issue with three would lead me to an installation problem.
With you being an armorer with experience with the AR rifle I would assume trigger and hammer springs will be installed correctly. With all due respect, three lowers three walking pins, I would definately look at your spring installation first in your troubleshooting sequence. If the lowers or parts kits were purchased at the same time there is always the possibility that you were unlucky enough to receive a bad batch of one or the other. Maybe even the pins don't have the grooves cut deep enough or are non-existent? |
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Quoted:
I can understand the possibility of one lower having an issue. But an issue with three would lead me to an installation problem. With you being an armorer with experience with the AR rifle I would assume trigger and hammer springs will be installed correctly. With all due respect, three lowers three walking pins, I would definately look at your spring installation first in your troubleshooting sequence. If the lowers or parts kits were purchased at the same time there is always the possibility that you were unlucky enough to receive a bad batch of one or the other. Maybe even the pins don't have the grooves cut deep enough or are non-existent? This. A/W pins only treat the symptom. |
| Some pins have two grooves (one in the middle and another closer to the side) while others have one groove (one pin will have a groove only in the middle and the other pin will have a groove only on the side) The Spikes LPKs I have installed had the single groove pins. Check your pins. If you have the pins with only one groove in each, make sure you have the one with the groove in the middle going through the trigger and the one with the groove on the side going through the hammer. If you have them in the wrong spot they will walk. |
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Quoted:
The past 3 rifles I have built, all with good quality lower parts kits and lower recievers, have been having the trigger pins walking out on them during firing. Has this been happening to anyone else? And just to be sure you know I am a Colt armorer and I have checked and recheked the rifles and the springs are in correctly. Pic of the assembled FCG, please. It's all speculation here without a good picture. |
| I appreciate the idea for the KNS pins but, the other posters were correct, I need to solve the issue. I can understand if there were more than 2 ways to put a hammer spring on but there isn't. They are all on the right way and the legs of the springs are over the trigger pin. Other than that what could cause this to occur?? |
Pics would be helpful.
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Quoted:
Some pins have two grooves (one in the middle and another closer to the side) while others have one groove (one pin will have a groove only in the middle and the other pin will have a groove only on the side) The Spikes LPKs I have installed had the single groove pins. Check your pins. If you have the pins with only one groove in each, make sure you have the one with the groove in the middle going through the trigger and the one with the groove on the side going through the hammer. If you have them in the wrong spot they will walk. Other way around. A pin with a groove in the middle needs to go through the hammer, it will be captutred by the J-pin. A pin with a groove on the side needs to go through the trigger/disconnector with the leg of the hammer spring in the groove. |
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Quoted:
Quoted:
Some pins have two grooves (one in the middle and another closer to the side) while others have one groove (one pin will have a groove only in the middle and the other pin will have a groove only on the side) The Spikes LPKs I have installed had the single groove pins. Check your pins. If you have the pins with only one groove in each, make sure you have the one with the groove in the middle going through the trigger and the one with the groove on the side going through the hammer. If you have them in the wrong spot they will walk. Other way around. A pin with a groove in the middle needs to go through the hammer, it will be captutred by the J-pin. A pin with a groove on the side needs to go through the trigger/disconnector with the leg of the hammer spring in the groove. Ah yes. You are correct. I did explain it backwards. I blame lack of coffee. 
OP, Did you get a chance to check your pins? Keep us posted on what you find once you get the issue resolved. |
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Quoted:
I appreciate the idea for the KNS pins but, the other posters were correct, I need to solve the issue. I can understand if there were more than 2 ways to put a hammer spring on but there isn't. They are all on the right way and the legs of the springs are over the trigger pin. Other than that what could cause this to occur?? I have never had the problem with one weapon much less three in a row. What do all three have in common? If it is not you obviously something is out of spec. Personally I have enough known good parts to make any needed comparisons. I still suggest that you swap one of the affected FCGs out with the FCG from a known good lower. |
| Cause of your problem is either the spring action of the "J" pin in the hammer is weak, not enough of the "J" pin is protruding into the trigger pin bore, the groove in the middle of the trigger pin is machined too shallow, or any combination of these conditions. |
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