Err, no. Remember that scene in Episode IV where they find the Sandcrawler with dead Jawas (right before Luke finds his dead foster parents), Obi-wan says that it couldn't have been Sand People since they only walk in single file and that only Imperial Stormtroopers are that accurate. Watched the movie again like 3 days ago, check if you must.
but we never see that happen. For all we know they fired 1,000 shots and missed but a few lucky shots hit the sandcrawler.
Every other time we see stormtroopers in action they have the worst aim ever.
Now back to Fett. When we see him fire in the Clone Wars and Return of the Jedi he is a terrible shot.
All Serg needs to do is hit him with 1 plasma grenade which will stick to his armor and then vaporize him leaving a helmet and a chest plate.