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Trigger reset issue, too light a load or too heavy a finger?

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Installed a CMC trigger in my FM9 lower that CMC modded for me to 2.5 pounds. Put about 1200 rounds through it without issue.


This is my first PCC and my speed is really starting to finally pick up. Last match I had five or six times when I was really  blazing at targets  within 10 feet and had to cycle bolt to get a round off. A round was in the chamber and there was no indication of any primer strike whatsoever on any of the ejected rounds.  I'm also shooting a REALLY light load.  I already talked to CMC and they said send it back because they have a lifetime warranty but I have some questions to the knowledge base here for informational purposes only.


The gun goes bang the VAST majority of the time and cycles perfectly UNTIL I start to really push it fast. After  my discussion with CMC I know that one of the mods done to get a 2.5 lb trigger is to lighten up the disconnector spring. 


Would a lighter disconnector spring cause reset problems,especially if I might be riding the trigger a bit, during a fast string?


would a light load amplify the reset issue?


CMC did say that I could have reset issues when I asked them to do a 2.5 lb trigger for me so I think I'll have them set it up for the normal 3.5 lb. If I don't ride the trigger it works perfectly but my old, slow fingers just don't get off the trigger fast enough during a fast run.

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What could be happening the trigger is not fully at the rear due to recoil backing the trigger from your finger when the bolt is cocking the hammer causing the hammer to fallow. If the trigger is not fully pulled at the time the bolt ramp depresses the hammer the latch doesn't catch it. 


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Another possibility is that since you said that it only happens when you are trying to shoot really fast is that you might not be releasing the trigger fully. That would not allow the hammer to reset. 


I have have seen this happen many times with pistols. So it may be something you want to check also. 

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One possibility is the hammer could be a smidge too short, not allowing the bolt to reset it.  A change of upper, lower, or bolt could fix it, or you may need a new trigger.  You can check it by pulling the trigger, keep it pinned to the rear, cycle the bolt by hand very slowly, then allow the trigger to reset.  If it doesn’t reset, then that may be your issue.  If you cycle the bolt quickly the momentum of the hammer will allow it to reset.

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The trigger resets as it should. I installed a new 3.5 lb CMC trigger that I just unboxed and the reset is significantly stronger. I think I figured out the issue and it's I'm sure my doing.


I shoot USPSA and I also shoot a Canik TP9SFX 9mm pistol that is tweaked and has an awesome aftermarket trigger with a super short reset. If I make the effort of completely  breaking contact with my trigger finger and the trigger on the PCC I have zero issues.  It's obvious I can't ride the trigger on the PCC like I can with the pistol.


Ive been shooting the pistol for about a year now and I just started shooting the PCC- I'm obviously going to have to learn to shoot each firearm differently. Is it typical that AR-9 triggers require a little more movement to reset?

Edited by copterdrvr
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Well, I'm a dumb @ss!  The problem was I somehow screwed up my powder drop adjustment and was not dropping the appropriate amount of powder as in too light.


The part that faked me out was that when the gun would fire it would eject the fired case without any problem AT ALL so a powder issue never entered my mind. I took a different batch of reloads this morning and no matter how fast I pulled the trigger, they all went bang and I mean I slapped the trigger as fast as I possibly could-sounded like a damned machine gun!  I had one mag left over of the previous batch of reloads and they had numerous failures to reset. When they fired, the empty cases would eject just fine. Again, my only defense was that when they fired they ejected just fine......


Think I'll be alittle more cautious when I set up my powder charge now!!!!  What a maroon!!!! (Bugs Bunny days!)

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