I'd go with Raging Bull, merely because it has more uses than the XM25. XM25 is good for OA and Grinding behind counters. It can't loot, can't do active grinding, can't PvP. The Raging Bull can PvP, OA, Grind, Loot. Pretty much anything you want, not to mention .50 is cheap enough to buy a huge stockpile, and depending on how often you loot, last you for a good month or so.