Want a B+ grade BCG for a D- price? Here it is. PSA 8620 M16 $79.99
Is an 8620 bolt the top-flight standard? Nope. But it's generally good enough. It was the standard
not so long ago, and will be equal to the challenge most shooters demand from their ARs. Good product, probably worth $150 when considering the 'real value' vs most other BCGs out there. Viable option for anyone looking for an affordable spare or attempting to upgrade a 'big box store' (DPMS, Bushmaster, S&W, etc) AR15.
This is a solid BCG. I would not choose it for my go-to $1500 setup+, but it'd be fine in the previously mentioned roles (minor upgrade, spare, or driving a $700-900 build). It can be the ideal spare at about $87 delivered. I've used a couple of these for builds and have been pleased with the quality throughout.