What are the various build order's I can give that will allow me to complete this achievement?
Train 10 Marines during the first 320 seconds of a single Melee game
6 Supply Depot
8 Barracks (first barracks is still being built use another SCV to do this)
Retask SCV's to mineral collection when they're done building
When the first barracks is finished start building marines in it (6-7 I think) When the second barracks is finished build more marines out of it (3-4)