That makes sense, but if I load anymore of these 150's I don't intend to use the same charge.  I got them all shot today, best 10 shot group was 2.8"x3.1".  Nice round group, no stringing or odd fliers.  Nobody else showed up at the single bench range today, so I got to take my time.  I also shot some 168gr Nosler BTHPs over 40.7gr of IMR4007 and they grouped about the same overall.  Might be about all the rifle has in it with these shorter shanked bullets, which is the same conclusion I came to last year before deciding to shoot it at Camp Perry.  This is the one with the free floated barrel, I'll be playing with the unfloated one next, going back to the .3105 174gr bullets.