I have several points of comparison for the Win vs the Weatherby. I've worked up loads in 3 different 300 WM with 180 Gr Accubonds in the past year. Powders were RL22 and 7828. All three seemed to max out around 3100fps, plus or minus 50 fps. Barrel length was 24" on two and 26" on the third. One Lilja, one Benchmark, and one factory MT Rifle Barrel. This fall I had the factory MT Rifle rebarrelled to a 300WBY in a Lilja barrel, 26in. I did limited load work due to timing prior to hunting season. 180 Accubonds over 7828 reached 3345fps and 180 TSX reached 3326fps over 7828. Accuracy was comparable on either with sub 5 shot 2" groups at 300 yards with little work.
I would recommend the 300WM to anyone that purchases ammunition and the 300WBY to anyone that reloads or is comfortable with a much smaller yet more expensive selection of loaded ammunition but wants a few fps and the name WBY. I happen to be a Weatherby fan and have several other WBY calibers so a 300 was a must at some point.
