The rated yardage for a club is an approximation, not gospel. Several variables affect the actually yardage of a shot.
Most of my TaylorMade R11 irons hit the ball further than their rated yardage, even into a head wind, if I don't change the spin adjustment setting on the ball.
But, they are pretty consistent and I have learned to allow for each clubs performance.
By the way - back when I played real golf I used forged irons (Ben Hogan, Apex PC - Percussion Center) and had to regularly visit the pro shop to have them tweaked back to the loft and lie for my swing.