little issue with my newly built AR..

[Mity2]

I finish building it yeasterday.

Nothing special. Simple 20" rifle with DPMS A-1 upper, and none-heavy barrel, mated with Anvil Arms lower with DPMS trigger kits and their buttstock.

Gun itself worked great. Although sight is not dead on yet(I ran out of ammo), but group was tight.

Anyway, my probrem is that it seems like my trigger pin kept backing itself out. i dont know if i didn't catch it, it it would worked itself out completely.

How can I fix this??

[Guns4Fun]

Did you build the lower yourself? If you did, you probably don't have the hammer spring properly in the groove in the trigger pin. When the hammer spring sits in the groove, it prevents it from moving. Check to make sure the hammer spring is installed properly and sitting in the grooves.

Another way to fix this is to buy KNS anti walk pins. Link here - the second item down on the page. http://www.knsprecisioninc.com/Trigger%20Systems.htm

[XD45]

Is it an anvil arms lower by chance? Chances are your gonna need a set of the KNS anti-walk pins guns4fun mentioned.

xdhatesAA45

ETA: would seem it is an AA, musta skipped that part the first time. But yea it happens w/ just about every lower of theirs i've seen ontop of some other things.

[D-FENS]

Same problem with the Anvil Arms lower. About every 90 rounds it works itself loose.

[pghplr]

Must be something about those AA triggers. Mine was bad right out of the box. XD45 switched mine out with an RR and it runs like a top.

[D-FENS]

Must be something about those AA triggers. Mine was bad right out of the box. XD45 switched mine out with an RR and it runs like a top.

It's the lower itself. I would imagine it's out of spec. I am not using one of their LPKs

ETA: You get what you pay for.

[XD45]

Must be something about those AA triggers. Mine was bad right out of the box. XD45 switched mine out with an RR and it runs like a top.

I think your issue came down to them installing installing the FCG wrong which is unfreakingbelievable being it came from the manufacturer that way, but it is probably a separate issue.

The issue w/ mine, d-fens, and sounds like Mitys among others is the trigger pin holes seem to be atleast slightly out of spec allowing them to walk a good bit and one side will eventually drop down into the receiver if u don't notice it soon enough. Simple enough to solve but you really shouldn't have to is what it comes down to.

[mojo]

I'm going to have to watch mine .... I have a AA lower and haven't noticed this happening on mine. I haven't ran it that much (waiting for cheaper ammo ) but I will definitely have to check it out now.

[Mity2]

Yes I think hole may be slightly out of spec. I can easily push the pin out of place by simply pushing it with my thumb.

i guess KNS anti walk pins would be the best way to go..

[Emptymag]

I hadn't heard anyone talking about this before.

Really? Lots of people are having this problem?

Mine hasn't moved a bit.
Granted, I've only got about 1,000 rds thru mine, but still, it hasn't budged. I know because when it was installed, I stopped tapping it in when the pin was flush with the right side, but on the left, it protrudes just enough to feel it. Nothing has changed since last year.

I have a Rock River Arms National Match 2-stage trigger.
My Anvil Arms lower is one of the PAFOA lowers from the first run.
Not sure if that makes any difference.