The maximum effective range of an m16, which is just a rifle, is 850 yards. The old known distance range for qualifying went to 500 yards.
I watched a SF dude in Eastern Africa ripping down guys on a roof 900 yards away one afternoon. He was firing a colt H-Bar version of the ar-15/m-16... he did this freehand, as in standing nonchalantly... my partner and I were trying to get on target for the same target- following stupid procedure of identifying the target, ranging the target, azimuth to the target, plotting the target on a map, THEN asking to compromise authority (engage the target). This dude just walked up, we pointed them out to him, and he started knocking them over.
Some of the ranges with today's systems are fantastical. The furthest I've ever shot was 1100 yards. I've never had reason to try any further. Some, now, are reaching over 3000m (that's meters) regularly. There is a shot recorded now in excess of 4k meters. I mean, with all the dope adjustments (ranging windage elevation and ballistics considerations) at that freaking range you literally have to take curvature of the earth into consideration.
Quick tale: a bunch of tali's stood atop a ridge some 2800m from the position of a patrol of mixed bag ASF, squeals, and a pair of Canadian snipers. They were literally flipping the finger and mooning them. Both teams could clearly see the other and they were antagonizing each other... night was setting in. The Canadian team broke out there new system, which at the time was still in R&D, which was a 410chyane. It has a scope mounted atop it that wires into a computer the observer wears in his ruck. He makes adjustments, or better said "approves" dope adjustments the computer offers. The computer reads wind speed at the shooters position, at the ballistic "maximum ordinance" (highest point bullet reaches enroute to target), and at the target. It registers humidity and temperature (every 20% increase in relative humidity lowers the impact a MoA and every 20 degree increase in temperature raises the impact a MoA).. all of this is done real quick like. The "scope" also records the shot... and that is where and why hilarity ensued...
The tali started falling over. They were watching the team engage them but they just couldn't grasp the shots could be those and frombthat distance.. instead they started scanning the sky- standing there dumb like looking to the clouds as if they were concealing CAS... but nope... while they looked up the Canadians selected another target and dropped them.
The story reminds me of another I'll quickly share:
First gulf war... an American F/A18 on the approach with a cowboy at the stick.. an Iraqi military facility in the open desert. The bird coming in nap of the earth (really really low) and setting free a rocket... the rocket had a camera... as the rocket approaches an Iraqi officer opens the door and starts to step out, and sees the rocket coming at him from some distance.... his response, reflexively no doubt, was to jump back inside and slam the door. My guess is he didn't make it.
Dark humor.. sue me. Life does that to some.