Are you sure they're Butternut?.... THere are a lot of winter squash out there..... I thought Butternuts generally had their classic shape from the embryo stage upwards.... I can guarantee they're not Bon-Bon or Festival (wrong colour and shape) but I wouldn't want to say they definitely are or are not butternut, it's just I'd be surprised if mine were that shape ... Indeed as surprised I was to discover that although the italians distinguish between zucchini and a long summer squash.... I'm violated if I can see/taste a difference :-)
chrisc