RE: What should I do??
IMO you are trying to beat a dead horse. You did not specify if the bullet's were VLD's, but if they are VLD's then good luck. The only time I have seen VLD's group is in a match chamber and tucked up into the lands. I have read in some Bench Rest forums that the reason they need to be tucked up into the lands(.005-.010) is that neck tension is a real problem with the bullet.
If you really want to make them work then turn your case necks. Measure your chamber, and buy acollet sizing die matched to your chamber. You have to get the neck tension right. And doing all this may not even be possibleif your chamber is too oversized or sloppy. Talk to BigCountry and see if he can help you with the runout, because that is where your true problem is. And from reading his posts he seems to truly understand runout.
I had aGunsmith tellme this one time"If the action is straight and trued, and the barrel is perfectly aligned, and your ammo is straight then seating depth(within reason)is not an issue as long as you have consistent neck tension." I am not sure those were his exact words, but I am close.He is building me a 22-250 right now.
Try the Sierra 175 grain bullet. Is shoots unbelievably in my 7mm Weatherby. I am assuming you are wanting a long range bullet, with a high BC, that will kill things way out there. IMO that 175 Sierra is the berries. And it is not a finicky bullet. Tom.