Mother shoots home intruder...after he cornered her in attic with her twins, 9

[neighbor]

172. A new ban with penalties for possession isn't realistic or reasonable either

The old ban did fail, with the amount of horsepower that it took to drive that legislation and the amount of time it was on the books... it really should have produced something.
But it was allowed to elapse because it didn't show any definitive results over the decade it was in place.

There was no serious decline in firearms-related crimes that everyone was hoping for.
Any politician would have loved to continue a piece of legislation that they can point to and say "look, it worked... see, I was right" but the 1994 ban didn't have that effect.

If you want a ban on weapons that have the same capability as the one used in Newton, you're going to have to ban semi-automatic weapons with any detachable magazine. Those that can fire a round every time the trigger is pulled and can have a box of ammunition attached to it for loading and reloading.

There are literally thousands of different types of firearms that have this capability, each with different and specific features. The only truly common feature that they share is the capability to fire every time the trigger is pulled. Another feature is having a detachable magazine, the part that you call a clip.

The typical rapid rate of fire that they can be operated at is around 45-60 rounds per-minute. If you have a feeding device that holds 30 rounds, then you can potentially shoot 30 objects in under a minute without reloading.
Most feeding device can be removed/ dropped in less than a second and replaced by another (full) feeding device in another 3-5 seconds typically.
You can draw your own conclusions about what's going to happen to your accuracy when moving this quickly.

Magazine capacity will have little to no effect on a person who has dedicated themselves to the act of killing another with a firearm. The potential shooter will simply bring more feeding devices so they can reload more.
This is exactly the case during the Virginia Tech shooting, where Cho was able to kill 30 others with just two pistols. One of them was a small-caliber design with a magazine capacity of just 10 rounds.

If there is going to be any definitive results of making specific firearms illegal, you will have to ban all semiautomatic weapons with a detachable magazine system.