More so if you have lucky shot, and you are beyond an extreme distance, I would guess 40m or so, you can fill up afterburn at like seriously 3x the speed. Not worth buying but there is definitely some unintended interaction going on here. I also just had a game where no matter how close I was I could not afterburn anyone.
edit: I tested every item I could find and didn't find a single one besides lucky shot that makes afterburn proc faster. Really not sure what's going on here.