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Posted: 3/23/2009 12:16:53 PM EDT
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Just curious if anybody has ever encountered any DPMS uppers out of spec enough that the takedown pin is virtually impossible to push through the upper's lug?
I have a brand new M4 DPMS upper assembly that is such a beast. I've tried the same upper on 5 different lowers and all had the same issue, but they all work fine with other uppers. I finally wound up drilling the lug out on the DPMS upper. I had to take out what I consider a decent amount of material - ie: it wasn't just anodizing or something clogging the lug - quite a bit of aluminum was causing the pin to point upwards at about the midpoint of pushing the pin through, so on the other side, it was totally misaligned with the exit hole on the lower. Took about 5 or 6 attempts to take out just the right amount of material. It all works fine now, the lug is still plenty strong, but it does make me wonder about ever getting another DPMS upper receiver in the future. Just wondering if anybody else has had similar experiences? |
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You may be out of luck. I'd have called them as well. You'd have gone the top of the list. Thay have
enough folks bad mouthing them, I'll bet they don't want another. I've had out of spec. parts from almost every mfg. None of them, want them out there. They've always been recified, PROVIDED I didn't try to fix. If they determine the problem is now yours. Which would be fair. Try Birchwood Casey, then Rustoleum auto primer. Tough as nails combination. I'd still email them. Good luck |
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Eh fixing it myself really doesn't bug me. I didn't take enough material out to have weakened the lug - I just found it surprising that it was pushing the takedown pin that far out of alignment. Worries me about ever using one of their uppers in the future. Most of my other AR's are EA, Stag, RR, Sun Devil, etc. I was mainly just curious if this was a rare occurance with one of their uppers, or something others had seen before. Interesting that you've had out of spec stuff from a lot of different mfgr's. I've never had an alignment problem like this after building 10 AR's, so it just kind of shocked me :-)
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| I picked up a stripped dmps a3 upper from midway a while ago when they had them in stock. I had the same exact problem with the rear takedown pin/lug. I sent it back to midway for a refund and bought from another manufacturer. That was the first DPMS product i've ever bought... |
That's DPMS for ya. I bought a stripped A1 style upper made by them, the charging handle groove was not machined to spec and no charging handles would fit in the upper. 
Also had a DPMS selector that was drilled too deep where the detent engages it, assembled everything and the selector would move at all, had to replace it with another brand. 
People bad mouth them for a reason. I have'nt seen many problems with their factory built rifles, but I have seen plenty of problems with their parts. |
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Quoted:
Alingment problems used to be common years ago. Back then it was almost always the lower. Happens a lot less now. Last one I got was a LMT made lower. one before that was an Olympic. Yeah I was going to blame the lower since I'd just built it, until I tried it with another 5 uppers from various manufacturers and it fit like a glove... plus it's a Sun Devil billet lower and I'd only ever heard great things about them. Fit and finish appears to be top notch. I know a friend I had back in Atlanta years ago had bitched and bitched about an OlyArms lower that he had these types of issues with. Now I know why he was irritated haha. |
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Quoted:
I picked up a stripped dmps a3 upper from midway a while ago when they had them in stock. I had the same exact problem with the rear takedown pin/lug. I sent it back to midway for a refund and bought from another manufacturer. That was the first DPMS product i've ever bought... And it happens to be an A3 from them in this case as well. Not sure if any A2's they make have similar issues. Could just be the A3's I suppose. |
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