Speed is cool, but accuracy is absolute! I have a 300 UM in a sendero. It is accurate, and deadly with my combo. The barrel is starting to show signs of wear, but still shoots well enough. I recently picked up a 300 win mag, that shoots it's #%* off, and it dosen't throw me around as much. As far as the 7 rum, IMHO, it is TOOOO much of a good thing. The 7 STW is about the most ( and perfect), amount of overbore that a 7' can be. Barrel life is ridiculous. Brass is getting hard to find for the 7 RUM now anyway. The 300 ultra, is awesome. They shoot well in the right gun, and are FLAT and hard hitting. The 300 win mag will last longer, and are very accurate as well. Spin the bottle on the 300's, but get a gun that can handle each. One last thought, 300 win mag brass is everywhere, and made by everybody. ( some VERY good brass)........