Turok: Dinosaur Hunter 100% Speedrun -  

It's entirely distance and weapon speed dependant. The closer you are to Thunder the less time you have to loadwarp since the frame his health is dropped to 0, you lose all control. If I'm using autoshotty I like to drum leftclick and pause nearly perfectly back to back to ensure I get a chance to loadwarp before the shot has travelled very far since it moves so look fast.