W748 can be very accurate with 150's as well. Check your load data, but something in the area of 42 grains is max.
W748 at 43 grains out of a re-barreled Kimber Montana. It does better with 130TTSX, but the 150 NBT is being used this year. Shot 6 groups total and they averaged 1.1inch.
100yards
300Yards: