Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
9/22/2017 12:11:25 AM
Posted: 9/12/2005 1:22:14 PM EDT
[Last Edit: 9/12/2005 1:23:09 PM EDT by pighelmet]
I bought a used, but not abused Colt A2 upper with pencil barrel off of the EE. I got it today and it seems that the rear lug is to long. I cannot get the lower and upper to close, nor can I get the rear pin to slide through. I tried taking the front pin out and pushing the rear pin home, but that made the front lug slide forward about a 1/16" and now I can't get the front pin to seat. The holes do not line up.

It looks like the rear lug is a bit to long, and is "bottoming" out on the floorplate of the lower receiver. Can I hand file it down a tiny bit? Will that alter the strength any? Ugh......

This will by my top secret "pigg-A-pator" project when I'm done....and yes, I am painting the whole thing too.
Link Posted: 9/12/2005 1:24:57 PM EDT
a problem/fix that the rra's have

file it if you feel like it.


the lug that is
Link Posted: 9/12/2005 2:07:28 PM EDT
Are you sure that you don't have a LARGE pivot Colt upper?
Link Posted: 9/12/2005 2:19:46 PM EDT

Originally Posted By eklikwhoa:
a problem/fix that the rra's have

file it if you feel like it.


the lug that is



This worked for me. Mine were Stag lowers though, note the shiny spot on the lug.



YMMV.

Danny
Link Posted: 9/12/2005 2:23:57 PM EDT
[Last Edit: 9/12/2005 2:24:52 PM EDT by j3_]
Look at the back corners at the curve in the back of the lower. That is where the upper lugs usually hit. There are two small radius cuts left out on the CMT made lowers I have seen that cause the rear edges of the upper lug to bind against the back corners of the lower some times.
Link Posted: 9/12/2005 2:42:37 PM EDT

Originally Posted By M4Madness:
Are you sure that you don't have a LARGE pivot Colt upper?



+1

Measure the front pivot pin hole. How big is it?

WIZZO
Link Posted: 9/12/2005 3:06:21 PM EDT
[Last Edit: 9/12/2005 3:07:57 PM EDT by pighelmet]
I tried two other uppers (not Colts..), and they both worked great. I don't have the tools to measure o.d. or i.d. I know, I suck.

I am pretty sure the rear lug is long. Here is a picture of the front one.
Link Posted: 9/12/2005 3:20:02 PM EDT
So I should shave a little off of the SIDES of the lug? Not the bottom?
Link Posted: 9/12/2005 3:35:56 PM EDT
It is not hard to tell the difference in a 5/16" hole and a 1/4" hole. Not hard to check the depth of the lower and lug length either. Piece of paper and sharp pencil will do that.
Link Posted: 9/12/2005 3:36:20 PM EDT
See how the bottom of the lug is tapered?

I did the back like in my pic ever so slightly until it went together.

I've done a half dozen or so this way, even a LMT upper or 2.

File slightly to taper back of rear lug, clean, fit, and Birchwood Casey Aluminum Black it and you can't tell it.

Danny
Link Posted: 9/12/2005 4:18:25 PM EDT
Normal RRA BS.
Link Posted: 9/12/2005 4:51:10 PM EDT
Sweeeet! Thanks Minuteman! Worked like a charm! Tight lockup and fits perfectly. Awesome!



Link Posted: 9/12/2005 4:54:40 PM EDT
WOW is that your blood on it? Seriously, looks great.
Link Posted: 9/12/2005 4:55:57 PM EDT
[Last Edit: 9/12/2005 4:56:48 PM EDT by Minuteman419]
You are welcome.

Sometimez I are useful.

Some on the board don't agree with this technique but it works. To each his own.

I hope that is grease and not your blood on the rear takedown pin.

Go forth young grasshopper and help others when you can!

Danny
Link Posted: 9/12/2005 5:04:10 PM EDT
So, is RRA making out of spec lowers?

Bob
Link Posted: 9/12/2005 5:31:27 PM EDT
I don't think so. I tried a Bushmaster upper, a M1s upper, and another "Frankenupper" and they fit perfectly on this RRA.

This Colt did not.

It fits well now. I have had good experiences with RRA. Thanks guys.

Soon the "Pigg-a-pator" with breathe.
Link Posted: 9/12/2005 5:38:45 PM EDT
whats the red stuff?
Link Posted: 9/12/2005 5:51:43 PM EDT
[Last Edit: 9/12/2005 5:53:22 PM EDT by Eli75]
I had the same problem with a stag lower and bushmaster upper. I sent the lower back instead of filing the upper. The returned one fit just fine.
Link Posted: 9/12/2005 6:13:19 PM EDT
good job !!!
Link Posted: 9/12/2005 6:52:51 PM EDT
The red stuff is Lubriplate grease.
Link Posted: 9/12/2005 6:59:13 PM EDT
Good to hear you got 'er fixed.

I've never had those problems with the RRA lowers I have nor the one's I've messed with at gunshows.

WIZZO
Link Posted: 9/16/2005 7:01:47 AM EDT

Originally Posted By Minuteman419:

Originally Posted By eklikwhoa:
a problem/fix that the rra's have

file it if you feel like it.


the lug that is



This worked for me. Mine were Stag lowers though, note the shiny spot on the lug.

photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=32241

YMMV.

Danny hr


Can you repost this picture? I've got a similar problem on mine.
Link Posted: 9/16/2005 7:04:39 AM EDT
Link Posted: 9/16/2005 7:22:57 AM EDT
Apparently it's a common problem with EA lowers too. That's what I'm currently dealing with. I called Del-Ton and the guy I spoke with said that he has 3 EA lowers with the same problem.
Link Posted: 9/16/2005 8:45:54 AM EDT

Originally Posted By Aimless:

Originally Posted By WIZZO_ARAKM14:
Good to hear you got 'er fixed.

I've never had those problems with the RRA lowers I have nor the one's I've messed with at gunshows.

WIZZO



It's a common complaint with RRA lowers.



Yeah, I know.

I guess I'm just lucky that all mine have fit together fine.

WIZZO
Link Posted: 9/16/2005 10:36:55 AM EDT

Originally Posted By DougR:
WOW is that your blood on it? Seriously, looks great.



Hell! I hope it's blood and not RED LOCKTITE!
Link Posted: 9/16/2005 11:31:19 AM EDT

Originally Posted By Ky_Bob:
So, is RRA making out of spec lowers?

Bob



I read somewhere (not here) that RRA does in fact build them slightly out of spec.

They do so in order to get a very tight fit on their parts.

I believe the spec calls for a slight variance to ensure universal compatibility

Down side?........................

You just saw it.
Link Posted: 9/16/2005 12:50:51 PM EDT
My RRA lower fit well with DPMS A3 upper. Didn't think it was overly tight, but this is only my first build so far.
Link Posted: 9/17/2005 7:16:31 PM EDT
This seems to be a common problem with some uppers and lowers. I first heard of it with regard to RRA lowers, but others are reporting it, too.

It is best to file on the corners of the rear upper receiver lug. That is the least damaging to every thing.
Link Posted: 9/17/2005 7:19:14 PM EDT
[Last Edit: 9/17/2005 7:19:52 PM EDT by cnatra]

I had a Bushmaster Dissipator & M4gery uppers that would NOT fit on a RRA lower.


I don't buy RRA lowers anymore
Link Posted: 9/17/2005 7:23:57 PM EDT
You should have just picked up a Colt Lower. Sorry but that is all I can think of
Link Posted: 9/18/2005 5:25:01 AM EDT
I had the same problem with a RRA lower and a DPMS upper---as well as a bushmaster upper. There are a few threads on different solutions on here if you can search back. In an nutshell, the two options depend on how tight your fit is. Some guys suggested file the upper, which worked for me on one upper. WHen I had the second problem, some guys suggested just "working" the upper and lower together a few times--with the help of a rubber mallet if need be. Now, I don't understand the mechanics of it, but that worked too and after about a dozen times, the upper and lower slid together nicely. TIghtly, but sill nicely and by hand.

Good luck
Link Posted: 9/18/2005 6:19:29 AM EDT
Top Top