Hi guys. I just got a DDM4 V7 upper. On inspection, it all looks near perfect besides the pivot pin and takedown pin holes. Each of those has the anodizing already worn through in spots. The pivot pin hole is worse. I tried to get a good picture. The anodizing is patchy and it looks like the aluminum in the hole is maybe a little marred too. It’s got a very rough look to it.
The upper’s been attached/detached from a few of my lowers maybe a dozen times. Funny thing, the upper locks up near perfectly with my lowers. Not too tight, but no wiggle. Think I should contact Daniel Defense about this? Or is this just chipped finish? I don’t really care about the latter.
I would be absolutely amazed if attaching/detaching the upper a dozen (or several dozen) times would cause the amount wear in the anodizing shown in your photo.
What did they look like before you began attaching and detaching the upper?
My guess is that after the anodizing was applied, DD performed some additional QC testing and determined that some remediation was needed in those areas, and
removed a bit of material (and anodizing). If this is the case, then it’s a good thing, since they seem to be dimensionally correct. This wouldn’t be the first time, and
certainly not the last, that a dimension was modified after the anodizing step.
Unfortunately, I didn’t look at the pin holes before attaching the upper to a lower. I was too excited. But, I agree that the attaching/detaching I did probably wouldn’t have caused the wear, even without applying lube first. My other two uppers don’t look near like that after much more use.
I wondered if DD did some work on the holes. It doesn’t really look like incomplete anodizing. I’m just concerned about the pin holes wearing out faster in the future due to the removed anodizing. But, the aluminum there should still be hardened from the anodizing?
FPNI. They’re feeding you a line. More than likely they found a dimensional issue during assembly where the pins wouldn’t fit and the holes were reworked and never re-anodized. The lack of anodizing isn’t likely to affect the fit, form or function of the gun itself but they sent it out anyway.
Yeah, maybe they fed me a line. I was a little surprised to find such a thing on a DD upper, but, as long as it is a non-issue, I’m good with it. Worse things could’ve happened. The gas block is straight, the rifling looks good, no gas port burrs, the bcg and barrel extension look great. I never assume I’m getting a perfect rifle or upper just because I spent big bucks. I’ve had function issues straight out of the box, from a well respected manufacturer after they did function testing. They took care of it though.
I’ve had the same thing on my upper and lower pin holes. Daniel Defense told me it does not effect function at all. Does anyone know if it can affect overall lifespan of the lower, though?
Kinda. Wear is normal in all areas where parts are moving against each other and creating friction. I imagine the less you take your rifle apart, the less wear you’ll see in the pivot pin areas.
If this isn’t an uncommon thing for DD to do, I guess it can’t really be bad. DD knows ARs well. But, pivot and takedown pin holes seem like a bad area to be without anodizing to harden the surface against the pins. I separate uppers and lowers frequently and it feels like there is friction in there, even with grease.
Maybe not bad, but not good either. At the very least indicative of a broken process. There’s no good reason that these receivers shouldn’t have been re finished.
The only reason I can think of is that re-anodizing would, as far as I know, slightly decrease the diameter of the pivot pin hole and potentially lead to fitting problems again. But, maybe that could be accounted for in the amount of removed material before re-anodizing. I’m tempted to ask them to switch over the parts to a new receiver, but I don’t want to argue with them about it.
They’d have to ream slightly larger than re-finish. Then hope it’s the right size. Type III anodizing can be as thick as .003". Doesn’t sound like much, but can make a pin hard to get in. Frankly, I don’t see a single issue with them reaming to size.
That’s a call they’re supposed to make through nonconformance reporting and quality/engineering disposition. If they can’t meet the requirements (all of them, material, dimensional & anodizing) through rework, the parts get scrapped, or regraded (blem). They basically shipped non-conforming (blem) receivers and sold them as 1st quality, only question is whether they did it knowingly because someone would have to sign off on the decision to do it under any standard quality system.
