I wonder how much of this FA is seeing with these new BCG's out there. I would sell the bolt and get a FA bolt. They own both pieces then. They have been doing this longer than most, they know their parts.
I got to tell you guys all these new companies rushing parts to market with little or no budgets and minimal R&D is very concerning. Making a precision part is one thing. Having a complete understanding of how the rifle functions and what dimensions are critical to proper function and safety might be something else.
Personally I am not a fan of risking my face to do testing for others.
Hell I recall Matt's .308 Young MFG carrier was not right and these guys are the best in the business with the AR15 stuff.
One of the things Manta is pushing for is a set of published specs rather than everyone trying to reverse engineer.
I understand everyone is anxious and parts are hard to come by and it's forcing many to buy hardware from unknown or lesser knowns. This is one of the reasons we push the headspace verification here. I commend the OP for not just "going for it" with blind trust and risking personal injury. This topic could be very different had he not.