AR15 Blemish vs Defect? (Las Vegas) 5/21/2020

In the first part of the video I called the bolt catch/release a "mag catch, mag release". Coffee must have been wearing off.

What constitutes a blemish on some of my AR platforms. What's acceptable and what's not? I think so long as the manufacturer is up front with it then it's not a problem. Some are a little secretive or don't mention anything at all.