See, at first I thought mine was the upper, because the garbage upper had problems, while the better upper fit.  Now hearing that your lower is having issues as well...     Then again, as with mine, it is a low-end upper that does not fit.

  One of my Aero lowers was super tight, one was not.

   Not sure who does machining for whom, but I know a few people have had similar AP problems.

   I'm a fan of Anderson, had a few quirks with them but easily corrected.  (they parkerized/coated after they drilled and tapped the pistol grip threads, requiring reaming them out).

 

As well, doesn't Anderson use a shorter, proprietary PG screw?

I haven't had a problem with them using the screws that came with the Magpul MOE grips. 

No. No you do not.

BTW, did anyone else have similar trouble with their Aero Precision lowers from the Coleburn deal?  Or is it just me and Kaso?

I have had one that was tight all the way around.  Pivot pin especially is tight on that one.

I had one that had gunk in the safety detent hole.  Had to drill it out to get the safety detent to seat against the safety selector.

I have had four that assembled just fine without issue at all.

I still have two that I have not assembled.

I've built a few AR's on andersons.
some are to spec, some aren't. it's only the pistolgrip screw though. everything else is always in spec.

I have purchased Anderson lowers on three different occasions.  The first batch had to be tapped the rest of the way.  The last two didn't.  Seems they heard the cry of the masses and repented of their short tapping ways.

Ne'ermind, return shipping has been arranged (for free, no less!).

 

So far, I've actually been very pleased with their support, other'n a few quirks...

1) I got the shipping confirmation email (with tracking info) the day after the upper arrived (which, honestly, is probably due in part to the fact that I live in the next state over, but the email should have gone out sooner).

2) They have multiple people checking one support email account - this is both good and bad.  Good because the "conversations" stack up, and let everyone who reads it see what's going on, bad in that, if the customer starts a new thread, it will not update the original "conversation".  For instance, I had been "conversing" with one support agent ("D"), and got another ("R") when I called in and requested an RMA number. My original "conversation" did not have that info, so I had to tell the "D" that I had requested the RMA from "R" and already shipped out the upper, when "D" sent a follow-up email to the original conversation.  What this tells me is that, if they have an internal support ticket system, they might need to engage with it earlier with regards to requests for support and possible returns.  I should have already been in the system, for "R" to update and "D" to double-check on.

In all honesty, this is nit-picking.  The guys I dealt with were polite and attentive. I can't complain.

Update: They've already processed my refund. Nifty.

That's a good thing. 
Took them long enough to get a solution.

I just got an upper from them.   The 20" Nitride with the MOE handguard.   Fit my Anderson lower just fine.   Shipping was reasonably fast too, I was expecting to wait another week or so, but it showed up within a few days after I ordered it.