Sorry if that seems pedantic, but the media uses the understandably easy confusion between the two to misrepresent issues around gun rights a lot.
My point? Semi auto AR-15s are every bit as effective and deadly as their fully automatic military counterparts. Whether civilians should have such weapons is another discussion.
With a 30 round mag and a cyclic rate of 700 rounds per minute (AR-15 mods run 700-1000 RPM), you get a little over 2 seconds of trigger time. That assumes you don't experience a jam, which is very likely with an AR-15 variant modified for automatic fire, and because of the weight distribution and recoil deflection, you won't hit anything you aim at after the second round leaves the chamber. So, if they are packing fully auto AR-15 mods, I'd be wayyyyy less concerned than if they were using semi automatic.
But yea, legal fully automatic weapons are not cheap.
And the people who confuse the two often talk about banning semi-automatic firearms (which ends up being just about all of them).
In general, yes. To play devil's advocate though, accuracy/controllability is not really needed if your goal is just to spray as much lead as possible into a densely crowded area from, say, a hotel room above.
Such domestic terrorist events are extremely rare, but I would guess in these specific cases where the goal is to spray as many bullets per second as possible into a crowd, full auto + large magazine is going to kill more people than semi auto.
Clarification: to acquire legally. It is not nearly that expensive black market.
I'd strongly argue against this point. Most hunting rifles have 5 round mags (legal limit for hunting in a lot of places). They won't accept 30 round mags. They're also chambered in more powerful calibers which have much more recoil.
An active shooter with his dad's hunting rifle is much less dangerous than the same shooter with an AR-15 with 30 round mags.
Why not? Seems like as long as the magazine can protrude from the bottom, you can have any capacity magazine you want.
Sure, you can make an unreliable automatic from a semi-auto easily. But it's a far cry from a commercial/military product.
It’s not like WWII rifles had wooden furnitures as luxury items.
One could make [1] their own in 2020 illegally with the hand tools you find at an Ace Hardware Store.
With a large magazine it would be a different story though, you are right about that. This is why I think that it's good to have fully auto by design weapons be illegal (think the SAW, or the M240), along with magazines above 30 rounds.