In New Zealand they used to pay people to shoot deer as there numbers were out of control and were just wrecking the place, and shooting three in one day would be a piece of cake.
To say that socially, environmentally and ecologically Scotland and America are a different would be a massive understatement.
I'd also just stick to your 308, and like Unclenick also pointed out, bullet selection will have a huge difference to wind drift characteristics.
But in 30-40mph winds any shot with any caliber is not going to be an easy one.
Which part of Scotland do you live in?
I've heard that to hunt deer in England and Wales can be a difficult exercise, as its either hard to find spots to hunt them, or people charge you to do so.
But Scotland has deer galore.
Have you been to shootforum.com, its a UK based forum, and is a lot different to this one, with most of the articles/threads being a lot more relevant to you, not surprising seeings as 99% of people here are American.