Yes I find it interesting also,with the evolution of the shotshell 99,things have become so precise that the selling point for most of our major manufacturers is this #'s game.The duplex load combines the knock-down power of heavier shot with the smaller shot to produce more projectiles/bullets in ther airvia more hits.A good selling point no doubt!!But with that said a load of conventional 4,5,6's that pattern 85% at 35 yards will lay a gobbler in the grass everybit as dead too!!Hows that for a middle of the road reply!!!