According to VLTOR, 14.5 inches is the ideal barrel length for manoeuvrability. It’s easy to move through tight spaces, balances well and yet still provides enough velocity to make a speedy round fly downrange. The issue is that a 14.5 inch barrel wasn’t giving them enough back pressure to reliably cycle the action, but 15 inches was perfect.
While 15 inches might be perfect for manoeuvring and reliability the ATF is convinced that the extra inch is the difference between a civilized society and hordes of armed anarchists roaming the streets and causing terror. So instead of being able to swap the muzzle device for a muzzle brake (that would be great in competition shooting) or an AAC silencer adapter (for, you know, silencers) they pinned and welded on an A2 flash hider.
VLTOR doesn’t see this as a problem, as they believe their customers just want an A2 flash hider. But by not allowing the customer to make that decision it limits the usefulness of the firearm. In this writer’s opinion I would rather have the extra inch of barrel and deal with the reduced manoeuvrability (however slight) for the benefit of being able to change the muzzle device without angering the powers that be at the ATF. Because really, an inch isn’t going to make all that much difference. In my opinion, at least.
EDIT: The engineering department at VLTOR responded to this article. See the response here.