Wouldn't registering all firearms be a massive overhaul?
Wouldn't an extended prison sentence for possessing an unregistered firearm be a massive overhaul?
Seriously, those who intend to do harm are not concerned with your proposal. They will not be arriving at these gun collection stations with the assault weapons in hand. They will not answer the door and willingly hand over their HCAW when the local popo come calling.
And I'll repeat, if your real concern is school security, address that. Lock the doors, no one in, no one out is a great start, Yes, it will make schools look a little more prison-like but, quite honestly, that's the world we live in.