The photos show to have a Nickel Boron finish coating. That’s a good sign as preferred finish over chrome. I’m thinking if it’s a Brownells BCG, ToolCraft could have made it for them, or several other companies like Anderson come to mind. Some might only make the carrier and use a different manufacturer’s bolt.
Regardless, if it is indeed a Brownells BCG, they wouldn’t sell crap and have a lifetime warranty on it.