(v23, linux)
Here goes picture how enemies were able to hit us (had to make a panorama, that map is big):
So the boss shoots Sam through the building as highlighted. Hope it doesn't look am unable to draw a straight line.
To get the proper trajectory, naturally, had to take into account the rain humidity having impact on the bullet's drag, its drop due to gravity, make adjustments for gyroscopic drift, and don't forget the wind... Well, at least you have the picture.
The bottom image is when another enemy shoots throught the building.
Think tried to step on Sam's position and other nearby, but got no los on the boss from there. Like it's only one way.
Btw. that's around ~30 tiles? The boss has a pistol (Eurocorp Nemesis, max effective range 10) and shoots like for breakfast. My snipers have also a fair CTH above max (think even ~50% at 20 tiles). Np on its own. However, given the maps, if the effective range is to serve purpose of distinguishing weapon types (thus also for enemies to shoot from various distances), it serves it only to certain extend - due how well the skill overcomes penalties. It's a similar to close with rifles. So in case it's desired for effective range to have a considerate impact, I would suggest to up the constant for penalty above max distance. And perhaps give pistols even faster drop (if possible) as well as lowering the maximum for pistols. And/or if you can come with a way to balance and further vary the skill in terms how much it influences what aspect of various weapon categories, that could be even more interesting.