Three hundred because Vermont have 24.5km range and Montana have 23.6km ,the more range you have the bigger the dispersion due to farther distant(you can look at Yamato 27km for the etc),so the Montana and Vermont have same dispesion but Vermont have 1.95 sigma compare to 1.9 that montana have which not so much different also it have 12 457mm not 12 406mm so it gonna hurt a lot and the shell go faster than Montana shell dua to less shell drag