I have several xp's. Two of them in short mag configuration 7 and 30, also others based on the 350 mag case 25, 6.5, 30, 338, 375 and a 458 2". THe 350 bsed cased numbers seem to be more effecient than the wsm cases, and velocity is equal or better. For instance the 300 wsm gets 2850 before extraction gets sticky and the 30/350 gets 2975 wiht the same barrel length and bullet weight. The 6.5 is actualy a savage striker and does 2900+ with the 120's and 2800+ with th e 140's