I've been meaning to post on this thread, but swamped with Rokslide stuff. I didn't read all the posts, so this may have been covered.
I own the exact same rifle but in 7mm Rem Mag. I experienced everything you did with not much more than about 2.5" groups. I sent it to WBY and they sent me a new gun!
I did the standard Premo ammo sight in with that gun and got better than 2" but still not the 1.5" they guarantee. I can't afford to shoot that stuff and really started working on handloads
I gave no regard to bullet choice and tried a bunch. I finally found the recipe and it was what HellsCanyon said, seating depth. I had to go to max then back off a few thousanths at a time. I ended up shooting a Speer bullet, which is fine for a deer hunter, and a gun that will hold great groups around an inch with low Standard Deviation. That formula is located on our home page at
http://www.rokslide.com/2012-01-09-...rifles-performance-through-standard-deviation
My ananlysis on WBY is that they are a solid gun, well built, great function, but are not the accuracy kings they once were, especially in the lighter weight guns. I grew up around them in the 80's when a 1.5" group was awesome, but they've lost that edge now. Still love the gun, though.
Good info Robby! I had not seen this article previously... Any time you can take the subjectivity out of things it makes decisions easier. I think this makes a lot of sense.
Coop