[falar]

Short and simple. If you're firing at a target that is beyond the high side of the Extreme range for that weapon type, do you even get to attempt the shot?

[ProfGast]

Short Answer: You can't hit anything past extreme range.

Long Answer: I seem to remember there are/used to be rules for "Long Shot" where you might be able to roll Edge for a lucky shot that shouldn't otherwise hit.  Don't remember if it's still a thing in 5E though.

[SlipperyChummer]

A character can certainly try, but it won't work. The player could try to huck a knife at the moon, but he'll fail. No roll is necessary unless you want to check for glitches.

[happybjorn]

While the previous answers are certainly better, here is another possible interpretation.  Range is part of the environmental modifier, not necessarily a mechanical limitation on its own.  Can the table for the environmental modifier extend another column to the right and if so, what are the effects?  Can something (gear, magical vision, etc.) then bring the effective range back to extreme?

[falar]

Possibly Image Magnification could do it if it's not far beyond.

However, in the case I was GMing, the player definitely didn't have Image Magnification at their disposal.

[Novocrane]

Environmental Modifiers go to -10. I'd allow it, provided the attack can be justified.

[adzling]

Let's not forget ballistics and physics folks.
Maximum effective range is not only governed by how far you can see but also bullet trajectory/ drop-off, velocity and wind shear.
Tl:dr bullets have a maximum range irl for reasons beyond "can I see it".

[Prætus]

Let's not forget ballistics and physics folks.
Maximum effective range is not only governed by how far you can see but also bullet trajectory/ drop-off, velocity and wind shear.
Tl:dr bullets have a maximum range irl for reasons beyond "can I see it".

I would like to bring your attention to this tidbit here: http://dangerousmagazine.com/project/the-longest-sniper-shots/.  None of those weapons documented as being used have effective ranges close to the distances involved.  Most big bore marksman/sniper rifles are usually rated from 1000-1500 meters (roughly 1060-1640 yards).  Fine examples of "Kentucky Windage," since the scopes typically cannot be dialed in remotely to compensate at those ranges.

Just my .02¢

[SlipperyChummer]

Let's not forget ballistics and physics folks.
Maximum effective range is not only governed by how far you can see but also bullet trajectory/ drop-off, velocity and wind shear.
Tl:dr bullets have a maximum range irl for reasons beyond "can I see it".

I would like to bring your attention to this tidbit here: http://dangerousmagazine.com/project/the-longest-sniper-shots/.  None of those weapons documented as being used have effective ranges close to the distances involved.  Most big bore marksman/sniper rifles are usually rated from 1000-1500 meters (roughly 1060-1640 yards).  Fine examples of "Kentucky Windage," since the scopes typically cannot be dialed in remotely to compensate at those ranges.

Just my .02¢

I don't know, that is a guy who's "mastered the craft" firing in ideal conditions. Also, if it takes 4 seconds and change for a bullet to travel that far, that's literally more than a combat round. I think that shadowrun writers can be forgiven in this case, since it's not often that players will be a half mile away from stationary targets and have such clear visibility to them.

Maybe there could be some kind of trick shot or positive quality enabling attackers to go beyond the normal maximum range for a weapon. But I still don't think it's something anyone should be able to do.

[CitizenJoe]

There's such a thing as plot device or plot armor.  These things exist beyond the scope of the simulation that is the combat system.  They occur by GM fiat as the story requires.

[The Wyrm Ouroboros]

I previously had rules for extended-extreme ranges, but this was when there were gradiations in telescopic sights and the like.  Telescopic vision simply reduces range by what, one bracket, two?  I would permit another range bracket past Extreme, going by this thought.  Or this topic here.

[AwesomenessDog]

I believe 5e has a skill specialization for long arms called "long shots" which without a book to check what it literally is, only seems to be intended for firing beyond something already defined in the book (beyond extreme range). I however could not find anything already in rules for firing beyond extreme range, and if one were to codify it as something more than a GMs ok to take the shot at extreme range, it seems like a -10 to the shot to double the extreme range would make sense for several reasons:

The penalties increase cumulatively by 1 every time -0 to -1 then -1 to -3 then -3 to -6 which is a difference of 1, 2, 3 respectively so if you add -4 to the -6, it would make sense for the next theoretical range increment to be a -10 to hit.
The increments apear to be more or less doubling every increment so 1500 to 3000m or approximately 1.8 miles isn't unheard of even by today's standards, now add future tech and computers with rangefinders that can calculate wind speeds at all points on the bullets trajectory; IMO 3km should probably be end of extreme range.
Although the bullet should theoretically travel for 4+ seconds, the simple solution for weapon makers is make the bullet go faster; the .50 is an antitank rifle not because the bullet is big but because it goes fast enough that the sturdy bullet can pierce 5in metal plates. It's likely not 4 times the modern day travel speeds but it could easily be explained down to landing on target at the end of the combat turn; it's not like 1 second combat passes where people can move 25+m/s, 90km/hr, or 56mi/hr make a whole lot of sense either.
Bullet speeds do drop off as they travel, not as noticeably as an unaerodynamic object re-entering atmosphere, and assuming the shooter and target are on the same elevation, the bullet speed is often low enough that a hit on the extremities is often survivable with immediate enough medical attention; how does this fit in to the abstraction: once you are in extended range, a soft damage cap can be applied (things like called shot for damage could go past it but successes couldn't increase the damage than, say, the accuracy of the weapon).