Some "official" 40 times:

Nyheim Hines 4.38
Saquon Barkley 4.40
Rashaad Penny 4.46
Kalen Ballage 4.46
Derrius Guice 4.49
Justin Jackson 4.52
Bo Scarbrough 4.52
Nick Chubb 4.52
Sony Michel 4.54
Royce Freeman 4.54https://t.co/UjvazqWjUR

— Josh Norris (@JoshNorris) March 2, 2018