re: What's the best argument against an all out AR ban?

This is actually an interesting argument concerning the 5.56 AR platform vs a Glock (19) 9mm.

I can't believe I am contemplating this situation in light of the events but...

The cyclic rate is high enough in both that the finger and reload time will be the limiting factor. The Glock (since we are talking off the shelf and comparing to what the shooter used) has a 10% advantage in mag cap since the Glock high capacity magazine is 33 shots vs 30. Since the shooter used ~450 rounds (based on what I read) that would be one less reload. The Glock is more likely to have a failure to drop free though. The Glock has a lighter trigger pull (stock) than most stock AR platforms so one should have less finger fatigue (actually an issue with 450 rounds in quick succession). The 9mm round would be more effective at short range EXCEPT if the church had pews or other cover one needed to penetrate then the smaller higher velocity round might be an advantage though it would result in more through and throughs.

I think I would choose a AR from the two but don't see a lot of difference as I see advantages and disadvantages for each but honestly no huge difference in the effective rate of fire.