I did one right after the lapua case came out with the 37.5 degree shoulder and the shoulder moved forward just a bit. In a 28" Hart barrel with 1-10 twist it maxed out at 2950 fps with the 300 smk. It got excellent accuracy in the 2900-2950 fps range. Unfortunately it shot to good and I was offered to much money for it so I don't have it anymore opting to stay with my faster 338-378 wby's. The improved lapua is a very good choice for a big 338 if you have an action for it.