Issues mating upper and lower receiver

O

Olyar15

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Bowser, bc
So I received my NEA 7.5" complete upper, as well as the CCS stock from SFRC. I'm trying to mate it with my Olympic arms lower, and the two just aren't fitting together. The lugs of the upper will not align with the pins on the lower receiver. There is interference with the forend and the housing area of the pivot pin. I tried filing that area down, but there is still something else preventing the two parts from aligning and I still can't get the two pins in. So now I'm thinking, either bring it to a gunsmith and see if he can do something (if I can even find one. Anyone know of a decent gunsmith near Bowser on Vancouver Island?), or buy the NEA stripped lower and transfer the various small parts from my existing lower onto the new one. My guess is that would be the cheapest, given that they are on sale at SFRC. But I have never tried completely disassembling a lower. Is it difficult to do? I do have some tools like punches and a brass hammer, as well as an AR armorers tool. From searching, it looks like I need a pivot pin tool as well.
 
They should fit right together without forcing it... Some makers have slightly tighter tolerances, but it sounds like there's something very wrong with one of your components.
 
If you've mounted the CCS stock assembly and buffer/carrier set up, you have to slide the upper onto the lower level. That is you cannot pivot the upper onto the lower, it has to go on flat, from my understanding. Failing that, assembling a lower is pretty easy, but I'd use a new LPK as it caan be a bugger getting the existing parts out of a lower without losing a pin or spring somewhere along the line.

https://www.youtube.com/watch?v=qg-3u6XNlIo
 
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The stock is still in the box. Wanted to mount the upper first to see what it looked like. My guess is that it is the lower that is out of spec. I've had that gun since the mid-90's so maybe their CNC machines weren't as sophisiticated. I think the best course is to just buy the stripped lower and transfer the parts from my current lower to that one. I've seen some videos on youtube and it doesn't look too hard. Might even be fun. Just not sure what to do with the old lower.
 
I'm betting the problem is more likely with the upper. I also have an NEA upper (10.5") that wouldn't fit an ANY lower from ANY manufacturer without being modified! I ended up dressing the holes in the upper with a small file to make it work. It didn't take much but even a couple of thousandths out will make it impossible to assemble. Once I got mine on it runs like a champ and it's accurate

BTW: all of the lowers I tried with it worked fine with all of the other non-NEA uppers I tried . Not knocking NEA, just reporting my experience (my barrel also has the gas port drilled slightly off centre so the gas block is somewhat cockeyed, but ti works).
 
The NEA upper I picked up was the same issue when I put a FF handguard on it. I couldn't have the handguard turned all the way on or the nut or it would interfere with the lower. It's just the NEA upper being out of spec, in the end I had to turn the hand guard out a couple turns for it to fit. Anyway, this is what you can expect from their "quality". Hope your barrel is better then this guys...
http://www.canadiangunnutz.com/forum/showthread.php/1049540-NEA-15-Review-and-Range-Report
 
I know Olympic Arms had issues in the past .... not sure about the current stuff...

Google "olympic arms quality control issues" and you'll see what I mean
 
One other thing to check is that the hammer is cocked on the lower... Often it jams against the BCG when trying to close the upper.
 
Thanks for the info. I thought about moving the handguard forward a bit, but that would have left a small gap. Now there are some gaps I don't mind, but this one would bother me.

Here is a pic of my Olympic upper showing the spacing around the pivot pin lug:
M34nzMT.jpg


And the one on the NEA:
CY0nPjD.jpg


After filing down the housing around the pivot pin I still have a very slight misalignment:
1jkELhe.jpg


It looks like the lug for the takedown pin on the upper is contacting the inside of the lower. At this point I really don't want to continue filing away on either receiver and possibly ruining them.
 
Jesus... The hole for the takedown pin is wayyyy off center... Never seen such shoddy workmanship. The upper is the problem.
 
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Could be either part that is out of spec. An easy way to find out is to see if the lower will mate with another upper. Get someone with micrometers to measure the tabs on the upper that the takedown pins pass through. DO NOT take a file or some other abrasive to the tabs. If you do you will cut through the anno on the tabs and expose the soft aluminum underneath. Out of spec parts are a known issue with NEA.
 
TDC said:
Garbage lower and garbage upper, I'm not surprised. Best of luck.

Tdc
Click to expand...

Ouch. Well, I'll be the first to admit that my Oly is not the nicest AR around, but it has been reliable, and with good ammo will shoot sub MOA (barrel is supposed to be able to do 1/2MOA). So I wouldn't call it garbage. Can't say much about the NEA upper, obviously, but it certainly looks well made.

BTW, I do want a nicer one, which is the reason why I ordered a Les Baer Custom IPSC model. But that won't be here for another year or so. In the mean time, I wanted something else to play with that wasn't too expensive. Hence, the reason I bought the 7.5" upper and CCS stock.
 
I'm telling you son it's the rear of the handguard that is keeping it from seating back enough!
I bought a stripped NEA upper...stripped it fit loosely on 3 of my lowers...Bushmaster, DPMS, and Dlask. I literally took all the parts off my DPMS upper and stuck it on the NEA. I have a YHM FF tube, the lock nut that is at the rear if the tube would overhang the back of the barrel nut by maybe 1-2mm when on my DPMS and no issue with it going on any of my lowers. On the NEA it was a no go....had to turn it out a couple of turns before it would fit. The holes for the pins are fine and the correct spacing, they ####ed up on the front end dimensions and need a little more material on the front for the barrel nuts to seat out farther.
Now, with that mono railed upper, you can't really turn it out....you would have to file the handgaurd back. With my YHM, the gap is suppose to be there....so not such a big deal.
I will end this by saying NEA truly is crap and not worth the headache...
 
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