284 needs a long action, and I'm not sure how reliably they feed from long mags (so I've read). 6.5x47 and 6.5 PRC can use a short action. The PRC shoots 140's at 3000-3100, the x47 is typically 2800 tops. The PRC barrels get HOT over long strings of fire (even with a heavy contour barrel), where the x47 handles it a lot better. x47 also has a good bit less recoil than a PRC or 284. The PRC has great factory ammo support, where the x47 and 65-284 doesn't. For hunting only, I'd pick a PRC. For shooting mostly long range, also PRC. If you want to shoot tiny groups and/or PRS matches, x47.