I have two 5 gallon jugs filled with water, not thick plastic but the flimsy stuff like a milk jug. I thought about putting these front to back of each other, and put them at about 25yds. I just found some federal tactical HST ammo, and wanted to try it out. Would this be enough water to stop the slug to get a good expanded bullet?? These jusgs are about 12"x12"x 20" high. what do you think. Will I need more jugs??