Reviving this for my recent experience.
I bought one of their first run BCGs last year and my rifle never functioned correctly, FTE/short stroking. A couple weeks ago I finally got access to another AR with a BCM BCG in it. Swapped the BCGs out, my rifle cycled fine, the other rifle with my RCA in it did not. So either a gas leak around the key or the fact the bolt didn't travel in and out of the carrier smoothly, like it was getting hung up on a burr or something (possibly resulting in a lot of the energy used to throw the bolt back being expended on it unlocking/rotating and not having enough to cycle afterwards). Rather than try to diagnose it myself, I sent them an email with my issue and figured I'd let them sort it out.
Emailed them and Chris got back to me quickly, sent me a label and UPS picked it up. They sent a replacement when they received mine and I received the replacement today. Kinda disappointed...it's clearly used (nitride wore off on the rails) and pretty dirty. Lots of excess oil. More importantly, the gas key was not staked at all. None of the 4 were present and there aren't any marks indicating it was ever attempted.
Who knows, maybe they sent me your old bolt. :)
Anyhow, I emailed them earlier, no reply yet. I'll certainly update once I hear from them. I'm not ready to shit on them yet, but I've been pretty easy going about things thus far and I expect better quality control out of a $250 BCG.