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Posted: 6/25/2008 6:28:13 PM EDT
| So I just finished installing my dpms lpk into my dpms stripped lower and I have a question about the trigger/hammer/disconnect function check. I cock the hammer back, it stays cocked, I pull the trigger and the hammer falls, I hold in the trigger and pull the hammer back and I really have to put some muscle on it to get to to engage the disconnect, in fact I think I was pushing so much it made the trigger creep forward slightly because I couldn't hold it back with my trigger finger. Is this normal? did I fudge something up |
| That all sounds normal to me. The proceedure you've outlined is also in the installations instructions provided with the Rock River National Match trigger. Yes, the trigger will move forward slightly when you cock the hammer, and if you really hold the trigger tightly back, it will take a lot of muscle to cock the hammer. The trigger HAS TO move forward a bit to allow the disconector to engage the hammer. |
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OK so in running a function check, with the rifle assembled. What happens if you charge it, pull the trigger and keep it back. With the trigger back charge it again. At that point everything should be as normal and when you release the trigger you should hear it drop from the disconnector hook to the trigger hook. You should then be able to pull the trigger and hear the hammer drop. Repeat a couple of times and see if it always works as expected. |
| Wow ok I'm a dumbass I was doing the test without the safety selector installed since I don't have a grip installed yet. I popped it in and tried it and the trigger doesn't move at all and the disconnector will engage just fine now. Thanks to everyone for the help |
Function check to be performed after COMPLETE assembly.  I bet there will be many folks that read this and don't do what you did because of it. One man's pain can ease another man's grief. Thank you for maning-up about it. Good luck with the build. Note: To 87GN, with nearly 10,000 posts you have never heard of the trigger group function test?? That was a joke, right? To LJP, if your trigger has to move forward a bit ,for the diconnector to engage, there is something wrong with it. |
That's not the function test I was taught in the military, is all I can say. |
on an AR15 the disconnector catches the hammer everytime you pull the trigger back and will hold the hammer until you let the trigger forward. when you let the trigger forward, the disconnector lets go of the hammer, and lets the trigger engage the hammer sear... now the trigger is reset and ready to fire... you might be confusing when the hammer sear is being engaged by the trigger with when the disconnector is catching the hammer... the trigger and the hammer move slightly to reset... the disconnector should always be doing its job or you'd have a problem... |
you weren't taught: charge the weapon pull the trigger hold the trigger charge the weapon let go of the trigger - listen for the "knock" pull the trigger every one of my friends who has been in the Army or USMC has always done that... it is almost instinctive that when i've let them handle my AR's, they do it before handing it back to me... that and close the dust cover... |
I think and I could be wrong he's saying with the upper off, holding the trigger back and pushing the hammer manually against the hooks isn't the test he was taught vs. the assembled rifle, hold the trigger, charge, release, listen for the knock... Like I said could be wrong, but I think the other is what he was saying |
i didn't even realize that the OP was checking without the upper... thats just goofy... i don't function check things till all the parts are in... |
That is exactly what i was taught...not with the weapon disassembled...probably because some E-2 would have cracked a lower receiver... |
I was following the video posted on http://www.lifelibertyetc.com/RangeBag/video/LLE_AR15StrippedLower.wmv for assembling an AR stripped lower and the guy in the video did the check just after installing the trigger and disconnector assembly but before installing the safety selector. I just watched that part again and if you look you can see his finger move forward with the trigger slightly. Once the safety selector is in, the trigger doesn't move at all(at least for me) |
Don't worry, what you did is NOT goofy by any means. Yes, when assembling a lower, i check disco freedom of movement, using the hammer, before installing the safety, but that is just to make sure it moves as it's supposed to. I do not function check until the lower is complete. I do not put the upper on until i function check the lower. I either use a hammer stop block, or my thumb, so the hammer does not strike the receiver. And yes, the military function check is doing the same exact same thing, only with the upper already mounted (so you have heard of it). I personally like to "see" it function, but "hearing" it function is fine too. Bottom line, either way you prefer to do it, Function Check before firing.
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And please note just for the record that the above was a butchered quote job and I never called it goofy.  I think it's perfectly OK to check your installation in the above manner, well with the addition of ALL the parts.  But on the discussion of general weapons function checking the assembled manner is the correct approach for that as it most closely simulates the operation of the weapon during firing vs. the unrelenting pressure and depth of your thumb. However during assembly, I too would check for disconnector grab of the hammer with the trigger back and grab of the trigger hook upon release. Just keep a thumb in the way so that if it fails to engage at the trigger hook level the hammer doesn't smash into the lower. |
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