Sounds like fun, but why junk arrows?
Shooting in and out of the plastic jug could tear them up, they could stick in the jug weird and get shot by your other arrows, hit the ground and bend/break when/if your jug hits the ground, etc.
Obviously nice, well tuned arrows will give you the best accuracy, but it's at a fairly close range if I remember correctly. There are just a lot of factors that could mess up a set of nice arrows.
Maybe "junk" isn't what you want to use, but you probably don't want to use your best arrows either.