How do i fix my jamming problem for my echo1 m4 commando?

i fire about 50-100 rounds in auto and the bb jams right at the hop-up or if i fire 150-200 rounds in semi it jams...i have put lubricants in the barrel,hop-up,and feeding mechanism. and its only the second day i have had it....so its not wear and tear....plz help i have a war in 3 weeks so i have no time to send it back.