I never understood the point of such an upper.
If you're bound to the 16" rule, why take away the ballistic advantage the extra barrel length gives you? It's like having all the downsides of an 11.5" barrel with none of the upsides.
cool. just a side note does anyone know why the ATF actually cares about the length of a rifle barrel. it just doesnt seem sensible considering we have pistols?
thanks
jake