Bill O'Reilly and Charles Krauthammer are roughly on the same page regarding assault weapons -- getting them off the streets is fine, but first, show empirical evidence that it actually matters.
One reason why Krauthammer, who supported the assault weapon ban in 1994, doesn't think it matters much?
Too many loopholes in Dianne Feinstein's assault weapons legislation.
"We've done this and it didn't have an effect, and the main reason is that there's so many loopholes. If you look at the Feinstein law -- the one she's now proposing to reintroduce -- she exempts 900 kinds of weapons.
The loopholes here are so enormous that it will have no appreciable effect on the homicide rate.
..... show me a law that will make a difference, and I'll support it."
A complaint about loopholes isn't necessarily the objection you'd expect from the Right. It's important to note, though, that Feinstein hasn't introduced her new gun legislation yet and has promised it will be "updated", so Krauthammer is jumping the gun a bit on characterizing it and seems to be judging it based on its 1994 image.