Milk jugs are not a good determination of how effective a particular round is. The closest thing to human flesh is ballistic gelatin and even then it's still not perfect. FBI requires I think 15 inches in gelatin, I could be wrong someone else might want to chime in.
Also just want to point out just because a particular round can penetrate 15 inches in gelatin does not mean it is going to incapacitate someone, its all about where the person takes the shots. Likewise people have been incapacitated with .32acp which doesn't meet the FBI requirements. There are way too many factors to put into consideration than how far a round penetrates in milk jugs or ballistic gelatin.