Re: 6.5-284 or 6.5-300 WSM
If you want a short action 6.5 NOW, then go with the 6.5/284. It has quality brass and is proven.
The 6.5 WSM is a proven barrel burner.
Winchester is working with a 6.5 WSSM (Winchester Super Short Mag) maybe. Heard several are trying it out. Called Winchester special projects mgr for this and he will not confirm or deny, but sure wanted to know where I heard about it and exactly what I had heard. Especially since I knew who was making the reamer for them. He would only confirm that they are testing a series of WSSM cases and do not know which ones they will come out with first. He admitted the market is there for the 6.5 if they make one. A decision on which WSSM cartridges will be marketed will be made in Nov and announced at the Shot show.
Wait a few months, buy your barrel, action stock, trigger, etc and see what happens in Jan. Make a decision on what the 6.5 WSSM looks like (if it comes out).