Jawz, I also have a Wby Accumark that I have upgraded. It is in 257 Wby but I do also have a 300 Wby. Mine looks like this now. (far from stock!)
This rifle has a McMillan A5, Lilja #7 barrel, Timney trigger, Marine tex and Aluminum pillar bedding, Leupold MK4 6.5-20x50. I can still put on my original stock(which I have opened up the barrel channel to accept the Lilja barrel) if I want a slightly lighter set up. I shoot a 115gr Berger VLD at 3325fps and it shoots like this very consistantly at 100 yards.
Here is a 300 yard group.
And at 500