I have a friend that rebarreled his 308 to the 6.5x47 Lapua with a Kreiger barrel and he has shot many sub 5 shot 2 inch groups at 500 yds. One was 5/8 inch.
I am thinking of making my 308 a switch barrel gun in 6.5/300 WSM
using a Kreiger barrel and of course another bolt for the different case head size.
I also saw one that Kevin built and would probably have him barrel my receiver.