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Posted: 9/12/2005 1:22:14 PM EDT
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. 
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Posted: 9/12/2005 1:24:57 PM EDT
[#1]
a problem/fix that the rra's have
file it if you feel like it. the lug that is |
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Posted: 9/12/2005 2:07:28 PM EDT
[#2]
Are you sure that you don't have a LARGE pivot Colt upper?
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Posted: 9/12/2005 2:19:46 PM EDT
[#3]
This worked for me. Mine were Stag lowers though, note the shiny spot on the lug.  YMMV. Danny  |
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Posted: 9/12/2005 2:23:57 PM EDT
[#4]
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.
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Posted: 9/12/2005 2:42:37 PM EDT
[#5]
+1 Measure the front pivot pin hole. How big is it? WIZZO |
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Posted: 9/12/2005 3:06:21 PM EDT
[#6]
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. 
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Posted: 9/12/2005 3:20:02 PM EDT
[#7]
So I should shave a little off of the SIDES of the lug? Not the bottom?
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Posted: 9/12/2005 3:35:56 PM EDT
[#8]
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.
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Posted: 9/12/2005 3:36:20 PM EDT
[#9]
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 
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Posted: 9/12/2005 4:18:25 PM EDT
[#10]
Normal RRA BS.
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Posted: 9/12/2005 4:51:10 PM EDT
[#11]
Sweeeet! Thanks Minuteman! Worked like a charm! Tight lockup and fits perfectly. Awesome!
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Posted: 9/12/2005 4:54:40 PM EDT
[#12]
WOW is that your blood on it? Seriously, looks great.
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Posted: 9/12/2005 4:55:57 PM EDT
[#13]
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
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Posted: 9/12/2005 5:04:10 PM EDT
[#14]
So, is RRA making out of spec lowers?
Bob |
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Posted: 9/12/2005 5:31:27 PM EDT
[#15]
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. |
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Posted: 9/12/2005 5:38:45 PM EDT
[#16]
whats the red stuff?
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Posted: 9/12/2005 5:51:43 PM EDT
[#17]
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.
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Posted: 9/12/2005 6:13:19 PM EDT
[#18]
good job !!!
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Posted: 9/12/2005 6:52:51 PM EDT
[#19]
The red stuff is Lubriplate grease.
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Posted: 9/12/2005 6:59:13 PM EDT
[#20]
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 |
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Posted: 9/16/2005 7:01:47 AM EDT
[#21]
Can you repost this picture? I've got a similar problem on mine. |
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Posted: 9/16/2005 7:04:39 AM EDT
[#22]
It's a common complaint with RRA lowers. |
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Posted: 9/16/2005 7:22:57 AM EDT
[#23]
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.
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Posted: 9/16/2005 8:45:54 AM EDT
[#24]
Yeah, I know. I guess I'm just lucky that all mine have fit together fine. WIZZO |
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Posted: 9/16/2005 10:36:55 AM EDT
[#25]
Hell! I hope it's blood and not RED LOCKTITE! 
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Posted: 9/16/2005 11:31:19 AM EDT
[#26]
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. |
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Posted: 9/16/2005 12:50:51 PM EDT
[#27]
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.
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Posted: 9/17/2005 7:16:31 PM EDT
[#28]
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. |
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Posted: 9/17/2005 7:19:14 PM EDT
[#29]
I had a Bushmaster Dissipator & M4gery uppers that would NOT fit on a RRA lower. I don't buy RRA lowers anymore |
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Posted: 9/17/2005 7:23:57 PM EDT
[#30]
You should have just picked up a Colt Lower. Sorry but that is all I can think of
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Posted: 9/18/2005 5:25:01 AM EDT
[#31]
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 |
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Posted: 9/18/2005 6:19:29 AM EDT
[#32]
I kind of doubt that anyone is intentionally making out of spec parts. When RRA had a bunch of out of spec uppers a few years ago they tried to claim they were "The new spec." for awhile
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