I've always thought that the best form of gun control was to require all gun owners to take marksmanship training so they wouldn't miss what they aim at. Also training on proper care of guns (cleaning, repair, and general safety issues). Gun owners should be licensed just as automobile owners are, and for similar reasons.
Automobile owners are NOT licensed in the USA.
I owned 2 cars at age 13, didn't even have a state ID at the time. Couldn't drive them on the street, but could operate on private property with no restrictions at all. Where I live in the USA, automobile drivers do not have mandatory insurance, nor mandatory registration of the track car in my garage, nor mandatory training to drive on private property.
Other consideration is that an mandatory rule will be abused by Sarah Brady and friends to try to make it more difficult to own firearms. For proof, just look at the gun laws in Chicago and D.C. both before the recent USSC cases, and the new laws they've enacted since the court struck down their blanket handgun bans. For example, Chicago had mandatory handgun registration, but closed the registration list, and dropped registered owners if they didn't re-register each year within a 2-month window for renewals.