I do have some trouble for a narrative perspective though. While I can certainly understand how pushing a roll for some long-term activities could be narrated. For example, taking a risk while climbing a cliff-face or really trying hard to persuade someone by resorting to spurious arguments that could easily backfire.
I find it much harder to explain how more instantaneous actions, say, a rifle shot can be pushed and what the potential damage could represent. I mean you don't know that the shot has missed until it has missed at which point it's too late to get a do-over.
"Oh crap, I missed... I try harder and roll again and, umm, hope I don't... strain my shoulder from the recoil?"
Anyone got some ideas how to present this to my players... I know they'll ask