Re: 6.5-284 or 6.5-300 WSM
The 6.5WSM is still in it's infancy as a true bench rest cartridge. I have been talking to some of the top shooters at Williamsport and several of them are shooting this round with great success. There are many experiments being tried on the standard WSM and Rem SAUM cases and modified wsm cases. Actually, a fellow shot several very small groups in competition with reduced velocity loads, around 3,025fps which is achieved with less pressure than the 284 case. Probably the most bold statement I heard was that the new short mag cases would dominate 1,000 yard events in the near future. This statemment came from one of the best shooters out there.
Now, to make things even more interesting, you have the Winchester Super Short Magnums. They have a 243 and 223 version so far but Kiff is already making reamers for the 6.5-243. I do not know what the case capacity is of these little rounds but it sure seems interesting!