How the heck do you aim from cover?

[thayanora]

I love playing snipers but it's basically impossible because from cover, Adam won't use the sights and just blind-fires.
Googling this problem says that I should be able to use the right mouse button from cover to use the scope, but it does nothing. Neither does using the middle mouse/right shift (the scope keybind from out of cover). I can't use Q or E to lean. As far as I can tell, there's not option in keybindings for this, so I can't reset it.
Adam, ex-SWAt cyborg, can't figure out how to peek over a box? Really? Or perhaps I am the dumbass for not understanding a simple tutorial... help me out guys? I've been playing the first mission for like six hours now. Maybe Adam is just going to murder everyone loudly this time. No stealth playthrough for me :(

[PNB]

Hold the right mouse button down, then push and hold W from behind cover.
Keep holding them down and you can then use A or D to move sideways, and press spacebar to roll.

Obviously you need to have your weapon in your hand to target, and it can
be a bit of a ballet trying to use the left mouse to shoot now, too,
but it all comes easily with practice.

Not sure about scope, but it auto-zooms anyway.
It won't work if there's a computer or something on the desk in the way,
or if you're not close enough to a corner. You can look over walls into lower levels.

[RobinOttens]

On controller, I need to be in cover, then move the stick forward to lean over it. Then I can aim. Otherwise Adam will just blind fire. Not sure how that works on keyboard or with a sniper scope. But yea, lean over your cover first. Took me a while to figure this out.

[retro_Ed]

Enable TOGGLE cover mode from settings. (under gameplay settings)
Use W for look behind cover
Press middle mouse for sniper rifle scope,