Schnell soon became one of the leading scorers in III./JG 51, reaching 31 by the end of July. In recognition of this, he was awarded the Knight's Cross of the Iron Cross () on 1 August, becoming the fourth in his "Gruppe" to be so honoured. When JG 51's collective total reached 2000 victories on 7 September with the Battle of Smolensk raging (doubling in less than ten weeks), Schnell's personal score had risen to 38. Over the rest of the year, as the weather worsened, his unit fought in the major encirclement of Kiev and then in the abortive attack on Moscow.