The New York Times managed to get someone experienced with guns and combat — former Marine infantry officer C.J. Chivers — to explain how the gunman’s vantage point and preparations opened the way for mass slaughter:
The possibility that Mr. Paddock used tripods, which two law enforcement officials said were in the room, indicates that he understood how to overcome some of the difficulties of his plan. Special mounts designed to fit the underside of a rifle and sit atop camera tripods allow the gunman to fire more accurately while standing. Military snipers use tripods in urban spaces, often setting themselves back from a window so neither they nor their weapons can be seen from the streets below.
These preparations, along with the downward angle of Mr. Paddock’s gunfire and the density of concertgoers, would make the shooting more lethal than it might otherwise have been, and more difficult to counter or escape.
When the gunshots started, videos showed, those in front of the stage dropped to their stomachs — often an adequate first measure when under fire. But on Sunday night, the decision potentially put them at greater risk.
Mr. Paddock’s position overhead gave him a vantage point over objects and obstacles that would typically protect people from bullets flying from a gunman at ground level. It also meant that inaccurate shots — the sort common to rapid or hurried fire, which typically sail high or strike the ground short — could still plunge into areas where people were huddled.
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Sheriff Joseph Lombardo of Clark County, Nev., said that at least 16 rifles, ranging from .308 to .223 caliber, and a handgun were retrieved from Mr. Paddock’s hotel room. A federal law enforcement official said that AR-15-style rifles were among them. The authorities did not detail all of the guns, or which weapons Mr. Paddock fired.
Several pounds of a nonflammable exploding target used for practice were recovered from Mr. Paddock’s home in Mesquite, about an hour outside Las Vegas, Sheriff Lombardo said. Ammonium nitrate was found in Mr. Paddock’s car in Las Vegas, the sheriff said, but he did not say how much was recovered.
[...]
The duration of the bursts, as recorded, suggest that Mr. Paddock cared little about the military’s prescriptions for automatic fire. Sustained rapid fire is difficult to control and causes many weapons, especially light weapons, to overheat quickly.
I wouldn’t think to use a light camera tripod for full-auto fire.
If you go over to YouTube and look for bump fire, you will find that any semi-auto rifle can be bump fired without any special modification. You simply hold the rifle loosely, not set against your shoulder, and hook the finger trigger in front of the trigger. But do not grip the rifle with the trigger hand or squeeze the trigger. Push the rifle forward with your off hand on the guard (better with a front post) to fire the rifle. The recoil resets the trigger, and constant pressure forward with the off hand continues the discharge.
Very difficult to control, and only useful in close quarters.
I was only vaguely away of bump-fire stocks, in my corner of the shooting world, because they’re not a serious tool for serious shooters.
Army studies found that full-auto generally puts fewer rounds on target — and that’s with guns designed to shoot full-auto.
To create a true “beaten zone” at long range, you want a real machine-gun, with a real tripod and a real “T & E” mechanism.