Not sure why I didn't get a notification on this sooner. I'd like to see one of these on high speed film. It doesn't look like the halves mate together as a single unit. The idea of being able to switch the bolt face out to shoot 40 S&W or 45 ACP is pretty interesting. To me, a caliber change is going to be an upper swap anyway, so why not just run separate, complete upper groups. And you'd have to buy separate bolt heads, so that eats into any cost savings.
But I think the bigger question is one of possible bolt bounce and reliability. The unit would likely travel backwards as a single unit. But I wonder if the the impacts as the carrier hits it's max rear travel would jolt them apart slightly? Or if they would separate as the carrier travels forward and impacts the barrel extension? Often, the forward impact causes a regular AR BCG to bounce backwards slightly before coming to its final position, locked into the extension. This is usually exacerbated with over gassing and high carrier speeds. A heavy buffer or increased power buffer spring can usually tame it. And it is usually only an issue with full auto fire.
Honestly though, is this a solution looking for a problem? It's not often that we see an AR pattern subgun in anything other than 9mm. Or maybe NFA just tipped their hand and intend to expand their offerings to other calibers and complete uppers.
Sort of the same thing, but not really. The bolt is designed for linear movement within an AR carrier, but the 9mm carrier isn't. I guess I'd like to see one run on FA just to see what happens.
