Originally Posted by
OlongJohnson
I no longer take the reviews of PSA blem stuff seriously. I was at the LGS when a guy was picking up his PSA assembled blem lower, and three guys were standing around it talking about how they could see nothing wrong. I was a good four or five yards away and thought I could tell what the issue was, so I walked over to confirm. The anodizing was flat, with the chalky residue wash of aluminum oxide. Should have been obvious to any detail-oriented person, even someone who hasn't spent as much time QCing anodized parts as I once did. It'll look OK if it's kept oiled, but it's far from correct.
I have no basis to independently verify this, but I've read that the buffer tubes PSA uses on their assembled lowers are 6061, while the ones they ship in kits are 7075.
I checked out some AP-branded lowers when another LGS was having a special on them. The anodizing was sticky to the touch, indicating it hadn't been sealed properly. The sealing process consists of dunking it in hot water for a period of time, so it's fairly difficult to screw that up. The parts would probably seem fine if kept oiled, but they weren't what they should be. In addition, the details of the machining left something to be desired. A matter not of cut corners, but corners left uncut. I decided the difference in price between the AP lower and the Mega Arms basic forged parts I've used is well worth it. Much nicer attention to detail in the machining and anodizing that's what it should be.
For perspective, a friend of mine decided to try anodizing parts he'd made for his car. Using the internet, a battery charger and buckets in his garage, his first efforts came out visually correct, much nicer than the PSA and AP items described above.