My experience has been that light barrel/heavy bullet combinations are more sensitive to harmonic variations and hence changes in accuracy and POI shift.
I finished by Larue barrel build with a Larue Upper and BCM rail. I need to get optics mounted and take a trip to the range. I concur with Rost that you need a base line load for testing. The Varget/69g SMK is popular. I also like 25.9g Benchmark/50g Vmax, which dups the Blackhills load.
Last edited by Grand; 08/26/15.
