Aero Precision Lowers/Uppers Out of Spec?

I've bought four lowers now from Aero Precision and the magazine catch would not fit properly on any of them. On the upper I bought from them, the takedown/pivot pin holes also did not line up. In the end, I was able to get them to fit only after using a dremel to widen the holes.

At first I thought that the problem with the lowers might have been my mag catch being out-spec, but I've used the same parts kits on several different brands of receivers and never had any problems. The same thing with the upper - the lower receiver I tried to put the upper on would fit other uppers no problem, but not the AP one.

Did I just get lemons or does AP not make in-spec parts? I want to be able to use them since my local gun store has their receivers in stock, but I find it hard to trust their QC after getting five bad parts in a row.