I'm a-ok with licensing and periodic renewals. The work I needed to put into my concealed carry permit made a whole lot more sense than simply being able to buy a gun following 30 minutes of boilerplate and a phone call. I'd like licensing even more if it was federal and superceded the arbitrary state-by-state reciprocity on concealed carry and bans on suppressors, SBSs, and SBRs.
Level I License: Revolvers and Bolt-Action, 10 year renewal
Level II License: All SA handguns and rifles, 5 year renewal
Level III License: Concealed Carry, 3 year renewal
Level IV License: supresssors, SBS, SBR, 1 year renewal
Thing is, some gun people would start screaming that amendment-conferred rights shouldn't require licenses...