PDA

View Full Version : Vltor Upper and Larue Lower not fitting. (PICS)


cody0341
09-26-11, 14:43
I was heading to the range and figured I would try some mix and matching. I tried putting on my vltor upper onto my larue lower and it is a no go. I first tried to line up both the pivot pin and takedown pin. The upper looked as if the the back of the upper wouldn't line up with the buffer tube. The second thing I tired was putting the pivot pin and then trying to put in the takedown pin, still a no go. The upper just would not line up. I just want to know if anyone else has had this problem? and also is the vltor and larue just a no go?

9866

9867
mtdawg169
09-26-11, 16:52
Looks like you may be getting some interference at the rear lug. Can you tell where it is making contact? Wear marks, etc?
Blowby
09-26-11, 17:06
If you care or have time remove the trigger group, bolt assembly and buffer. Eliminate all possible interference variables to just the upper and lower. Now determine where the contact points are with some machinist's bluing dye.
matemike
09-26-11, 17:17
Did you try to mix and match the other way? Put the LaRue upper on the Vltor lower.?.. if you even have that option. That might make the difference obvious
cody0341
09-26-11, 20:59
If you care or have time remove the trigger group, bolt assembly and buffer. Eliminate all possible interference variables to just the upper and lower. Now determine where the contact points are with some machinist's bluing dye.

The point of contact is the back of the upper by where the top of the buffer tube is. No matter how hard I push the upper down I am unable to push the pin in. I also tried this with the bolt and buffer out still same thing.
mtdawg169
09-26-11, 22:27
The point of contact is the back of the upper by where the top of the buffer tube is. No matter how hard I push the upper down I am unable to push the pin in. I also tried this with the bolt and buffer out still same thing.

Are you certain? The rear takedown lug may be making contact inside the lower, preventing it from dropping in completely. I've seen this happen with other tight fitting upper / lower combos. It is difficult to see exactly where they are making contact due to the lighting in those pics.