I have a dpms lower that I have only fired approx 200 rounds through. The pin holding the trigger group backs out after a few rounds. How do I fix this problem??
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I have a dpms lower that I have only fired approx 200 rounds through. The pin holding the trigger group backs out after a few rounds. How do I fix this problem??
Get a set (trigger & hammer) of anti-walk pins from JPRifles for $15.95.
Check the hammer spring is installed properly and goes into the grooves of the pin on the sides
As above or it's a broken pin. Personally I've never seen a pin break except for a DPMS pin. Either way get some preemptively from Bravo Co, make sure it's all in there right, and you'll probably be good at least in terms of pins.
First thing: Is it installed correctly? Incorrectly (upside down) installed hammer springs are a common culprit for this. Before buying anything, I suggest making sure that it is installed correctly. Pictures would be helpful, otherwise we can only guess.
Edit: Others already said it, I guess I take too long to write a post.
Take a picture of the FCG from the top and slightly angled.
I had the same problem with my AR. The problem I found was the for lack of a better term the protrusion on the side of the trigger that the trigger spring mounts on is ground off about half way down on the side of the trigger. The protrusion was not ground down enough to let the hammer spring rest on the trigger pin and hold it in place. I used my Dremel to grind down the back side of the protrusion further to where it would let the trigger spring rest on the hammer pin and that solved the walking pin problem on my AR.
You either have a defective or broken pin, or it is installed wrong. When you say "trigger group" do you actually mean the trigger or are you referring to the hammer pin?
Not to derail the thread or sound like a dick, but wouldn't it have been easier to just buy, at minimum, a new trigger by itself? I mean if the trigger QC was that "bad" to allow for the pin groove to not catch the hammer spring due to the 'not cut deep enough protrusion', I think i'd just ditch it and find something a little more in-spec. YMMV
If I could have went to the LGS and bought another trigger maybe. Unfortunately no LGS carry AR triggers so I would have had to order one off of the internet. A couple minutes with the Dremel fixed the problem with the hammer spring not resting on the trigger pin. I have put over 500 rounds down range since with no problems.
I believe he was referencing dremeling this part:
http://i1057.photobucket.com/albums/...psbfe63f52.jpg
Another Dremel-phobe
The man fixed the problem to his satisfaction. If I had a faulty standard AR trigger that I could fix with a little work (assuming the fix doesn't compromise safety or reliability) I'd rather do that than waste my time & money trying to convince someone they need to give me a replacement
Make sure the hammer spring legs are laying flat in the groove on the pin, my spikes pin only has one groove and the pressure of the hammer spring helps keep it in place.
http://i.imgur.com/iKPbOd3.jpg