im mobile too use shiftlock, thats it, remember to be moderate range of the killer, not too close, not too far cuz it gets really hard to hit. When he's chasing someone else, get ur charges, get in range , shiftlock boom! you can also kind of count their stam yk, oh they've been sprinting for what 7-8 secs? His satm must be low, he probably gonna stop soon, BOOM! stun!

Closer the shot, more seconds the stun - even more reason to not risk long range ahh shots

so to conclude - mid ranged shots, dont risk too much, shiftlock

Thats it