Backpacks, Explosives and Barriers, More questions from ye olde newbie Options

[FXcalibur]

Backpacks - About the concealability of gear: Can't I just shove my pistol into my backpack, surrounded by layers of cloth and other stuff? Would you rule that my hidden pistol can be be spotted by a visual-only perception check?

Explosives - Can I buy 'empty' or 'dud' mini grenades? I think GLs are noticably less noisy than guns, and I have an assault rifle setup which I want to use. I want a GV 4 on my barrel incase things get hairy, but for the Ares Antioch underneath, I want silent takedown rounds. Perhaps Rubber/Gel or just an empty minigrenade. I've check CC, they don't mention anything like this. I might have missed it though. Can someone provide rules? And while we're on the subject, what's the damage if I shoot someone within 5m? The grenade doesn't arm, but it has got to hurt.

Speaking of which, I can call shot and aim my GL like a normal gun, right? For example, call shot head with an Off-AP round. No need to use scatter, just treat it like a normal firearms test, right?

Barriers - Preparing for an upcoming run. We need to break through hardened material (32 barrier, I think) with explosives. How much C8 will I need to do so?