Let me describe how I see the situation in Denver.
First. This city is consisting of sectors. While the SIN (fake or not) is valid in all the sectors. Each of the sectors has their own licenses set. That's because they each have different norms. If you have a license for a gun or fake SIN valid in Pueblo, it might well be, that the same gun isn't legal in other sector.
As a rule of thumb, anything bigger than a light pistol is illegal, and having a license for it only rises the brow, as only police forces are allowed to use it.
There is ONE runner that is allowed to carry guns/armors in the team - that's because he paid 15 thousands nuyen for R5 Zone Defence Forces officer SIN. Unless you're prepared for such costs, I'd suggest you do what all others are doing - keeping the illegal things hidden and talking through the border checks and using basic citizen SIN.