I've done this on the easiest target shooting range against the AI.
If you select the target shooting range you'll see first the screen where it's showing your opponent. There you also can see which power-up your opponent is using. Look for the blue crosshair symbol. That's the blind fire. If you're opponent doesn't have it, exit and re-enter until you get an opponent with the Blind Fire.
During the game I let the AI steal my targets on top of the range so that it's power-up would charge faster. Eventually it will activate the power-up so that you can go for the 500 points which shouldn't be that tough on the easy shooting range. Took me less than 5 minutes.
Good luck!