Three questions rolled into one, in an area where I have no expertise at all, and two probably belong in another section. So I'm at the gunshow, and there's the cool Class 3 table. Normally, I just walk on by, but today..... So question 1: They have Serbu Super Shortys for sale. I need to get the AOW $5 stamp. I assume I need to do this before I buy the shotgun, but do I need to have a specific one on hold? Is there a part of the form that will require specific serial numbers, etc.? And how long does approval take, roughly? Question 2: There's a $50 difference between the one made off the Rem 870 recievers and the Mossberg ones. Is there enough of a difference to go with the Remington? And finally: Anybody have experience with mini 12 ga shells? I didn't even know these existed till a few days ago. Seem like a natural for a mini shotgun, but that has to be over-simplistic, I'm sure.