I have been kicking around buying a 357 round gun for some time. Well it's time to purchase. I am hesitant to buy the new colt based on some reviews. I think I have settled on a gp100 ruger. The gun will get some carry time. The question is does the 357 Magnum round perform better out of a 4 inch barrel as opposed to 3" ? I think I would prefer 3" but don't want to give up much velocity ? What says the revolver brain trust ?