I've noticed it doesn't work no matter who I shoot and I even have the bird nest... Like there is a small chance that maybe 1 out of 10 kills it will work. I even tried the AK and still no dice? Does it work for anyone else?
I only find stopping power effective when the enemy is running straight at me but it never seems to work when there is someone rushing at me with blindfire.
What it does help with is when they're running away.