I just installed a new RRA NM 2 Stage Trigger in my LaRue Lower.

While holding down the trigger and then pulling the bolt carrier back, the bolt gets hung up on something and wont go any further until I release the trigger.

Anyone have any ideas of what could cause this?

Why are you holding down the trigger? can you take a pic of the install job you did?

I'm holding down the trigger as part of the safety function check.  That way I know if the disconnector is working properly.  And here is the picture!

I may just be retarded be doesnt it look like the hammer spring on the right side is underneath the trigger pin?

I just double checked.  It's the picture.  Both springs are good to go.

id guess the hammer is hitting the disconnector.  you might want to look up some info on fitting the disconnector properly.  i think there are some links under the build it yourself sticky.

the hammer cant hit the disconnector with this FCG, and it's not a seperate component- it's installed at the factory. can you pull the hammer/trig and take a picture of them? kinda sounds like your receiver is out of spec.

Here is the picture.  I really hope you're wrong about the lower being out of spec.  I waited 4 months for this thing...

does the FCG function test just fine without the upper attached?

You've stated that when depressing your trigger, the bolt is not able to go back all the way.



Seperate the two halves.  While depressing the trigger, pull the hammer back into engagement with the disconnect.  Is it able to go all the way down?

Yes.  With the upper off the trigger passes all the safety checks just fine.  When the upper goes on is when the problems start.

With the trigger depressed I am able to go about 50 percent of normal travel before I meet some resistance.
From that point on I have to crank on the charging handle in for the bolt and carrier to go back far enough so that it is capable of stripping off another round.  
At that point I will release the charging handle (with the trigger still depressed) and the bolt and carrier will not move until I let go of the trigger.  
At that point the bolt and carrier will release and fully enter the barrel extension.  I've never seen or heard of this happening before so if anyone has any ideas, please don't hesitate to throw them out there.
This is only the third gun I've put together, so I'm still relatively green.  However, I'm not completely retarded...hopefully.

Are you running an M16 Bolt carrier? If so, for whatever reason - I bet it's catching on the hammer. Can you take a picture of the hammer from the side? Seems like there may be a notch or something on the hammer that's causing the bolt carrier to snag.

my $0.02

Sakic #19

I could see an unshrouded AR15 carrier catching - if anything...

I thought that might have been the issue as well, but want to know something pretty rad? My first gun I bought back in 2001 I put a RRA Match Trigger in and when I did it I put both the side underneath and had it like that for?? A couple years? It never had a problem...well other than the fact that there wasn't enough tension which caused the pins to walk. Ridiculous huh?

Well I figure I'd give you guys an update.  It is a M16 carrier and it is the 'old style' RRA NM trigger with the notch instead of the hump.  
I called RRA this morning and I'm shipping my whole lower to them so they can take a peak at it.  What a pain in the @$$...

Any pics or other info on the old vs. new styles? My two have both been purchased within the last 2.5 years or so, so I'm guessing their the new style. Didnt know there was a difference. Now you got me wondering. I have installed but have yet to test this issue on a new 16 BCG.