I actually DO have a practical solution. Any gun owner, whose gun is used in the commission of this sort of tragic slaughter, should be held 100% legally and financially accountable. They should be forced to pay damages to any victims. This would very much encourage parents, for example, to keep guns safely locked where teenagers can't get at them. No excuses. No exceptions. If you choose to own such a weapon, the death and destructions wrought by the weapon is on you. Period.
Insurance companies should be allowed to inquire about gun ownership, and to charge you significantly higher premiums, should you choose to own a weapon.
These are PRACTICAL solutions that don't involve taking one gun away from anyone.
Another practical solution. Have a gun buy back program. You get a voucher good for paying for higher education or the cost of a private school education. Will we get them all? No, of course not. But, any reduction is better than none at all. And the last few of these shootings have been by legally obtained/owned weapons (not illegally obtained....those tend to be used in drug crimes, etc, not school shootings), so we've got to reduce the rate of such ownership OR make the penalty for failing to adequately secure such a weapon very high to make sure people handle their guns responsibly.
If we spent as much time and energy focusing on this problem as we do on "terrorists" (which are just not that much of a statistical threat) we'd be well on our way to solving it. But, we do NOTHING. Absolutely nothing. And, the slaughter continues.