jocko said:
You won't go wrong with any of the 3 you mentioned
That's kind of the good news bottom line. There isn't, and can't be, a single "most effective" round for all circumstances. Any of those 3 rounds will probably get the job done in an average situation, while individually they might each have a particular set of circumstances where they outperform the others.
I've done some testing on the Speer GDs and the Hornady CD and the Hornady delivers exactly what it promises - expansion under just about any circumstances. However, expansion will
always come at the expense of penetration - there just ain't no such thing in this world as a free lunch. To me, it seems their best usage would be in calibers larger than .380 where over-penetration and the potential wounding of bystanders becomes as much of an issue as under-penetration. I think the Hornaday CD will be outstanding in the 38 spl +P, .357, .40, and .45. For the .380, I'm going to go with something that penetrates a little more. I like the Speer GDs better than the Golden Sabers, but I would not feel afraid carrying either of them.