Hi! Sorry if this has been posted before; quick google search and examination of the bug forums turned up nothing. This is an odd bug I've noticed while doing single pick challenges. The map is the exact same one Furnace Clans is on, tileset is Phoebus, and as clean an install as you can get (ignoring Cartilage modded into shells).
The setup I have is a 2z-tower with zero ground access to the enemy, and all enemies out of range of a legendary +5 Archer/Marksdwarf right up against fortifications.
Order the marksdwarf (pref. elite, so fortifications do not matter to him) to attack one of the out of range, inaccessible, enemies. In this case, its a zombie well out of range of the tower.
The marksdwarf will then start machine-gunning bolts at everything (remember: everything is out of range) BUT the target. In previous instances where I've seen this... oddity, I saw bolts fly 50+ tiles away at times.
In this case, the first bolt flies 33 tiles south and 11 tiles east... from a 1z high tower. And nails a zombie in the upper front tooth.
The second? Flies 39 tiles north and 33 tiles east, hits the zombie in the leg, and takes it down.
The marksdwarf will continue shooting at just about everything. Until he runs out of ammo. Cancel orders, he'll grab the next bit (I have an ammo stockpile, no bins, right under the tower). Also interesting, I have never seen him take out his initial target.
-could not figure out how to post pics: therefore, imgur gallery link-
Conjecturing, since I've seen this over multiple games, I imagine so long as the marksdwarf meets the following, he/she will have very high range:
A)Told to kill a target he is out of range of
B)Not able to access target to get closer
C)Has bolts
D)Is in a position where range is the ONLY issue (i.e. up against fortifications as low level marksdwarf, but otherwise clear line of sight to enemy)
O, and the guy hanging out by the u shaped bit of walls south of the tower? He's my vampire janitor, dumping the bodies down into a shooting gallery 12 or so z-levels below.