First and foremost: All weapons beside the Urban Combat have enough metal in them to qualify for Hot Potato otherwise simple gloves would render this illusion spell useless (and yes, that is one reason why I placed the HK UC in your arsenal)
Second: AP attacks of single bullets only take one point of damage away if they punch through a barrier (It's impossible for the barrier to stop 8 base damage with only 5 dice), so all you lose is 1 damage.
Third: I might have missed it, but I don't think Scary has gotten rid of the net yet, so -5. Also he is under hot potato for another -5
Just in case, I roll for him:
Resist Net:
11d6t5 4So yeah, Scary is free, but his gun is burning his hands
Forth: If he charges the barrier he won't be able to continue his charge in this phase - he'll need another complex action to get to Yang (which is the main reason Yang has cast the barrier - it won't stop bullets, but it'll stop others for the moment engaging him in melee)
Picking up the gun despite the felt heat is definitely possible for Scary, although I'd also allow you to say he didn't drop it in the first place, being a stubborn SoB.