California's (and other states') rules have a huge bearing on the issue, because they're clear examples of what gun control advocates are trying to implement since they're what they've actually implemented.

To have access to NICS you need to be an FFL. So you at least have to go to an FFL. They will charge you to do the check and federally required paperwork (which takes longer than 30 seconds). The only thing that the other poster said that isn't something universal at the federal level is the waiting period.

It's actually quite germane, considering that this is the way your proposal is implemented in real life.