Hey All,
I received my corrected mags from HBI last week, and everything works fine now. It seems that there was a simple mistake in the tool used to deburr the inside of the magazine after the new notch had been cut. I don't think they'd mind my posting this portion of the e-mail I received regarding the problem:
"What we found is that while they did go through our process correctly (meaning all of the checked/signed steps on the flow sheet were complete), our operator did not use the correct tool to deburr the inside of the magazine. You had mentioned that the inside felt flat and that you did not feel any burrs, which was true, however that back lip of the machined window is supposed to be chamfered or angled so that the rounds do not hang up. And it was not. It was just made flat. So you had a flat, but very sharp edge on both the bottom and top edges of that window on the inside of the magazine body, which explains why the rounds were scraping copper on the way down, and the follower hung up in that one magazine for you on the way back up.
We correctly deburred the magazine bodies, refinished that window, and tested every magazine with 30 rounds (load 15/unload 15/load 15/unload 15) and did not get any round catching, copper scraping, or followers hanging."
I would imagine that HBI won't let that mistake happen again.
Overall, HBI handled this issue as well as I could expect any manufacturer could. I am very satisfied and would easily recommend HBI to anyone considering their products.
Cheers, and many thanks to Phil for his help,
Dave