I wear a size 9.5 tennis shoe and size 10 boot typically. The size 10 alpha burlys fit me perfect with room for one pair of wool socks. They are the most comfortable rubber boots you'll ever own and are very warm as well.

 

My experiance with LaCrosse burleys is to buy your regular size and do not wear heavy socks. The heavy socks will make your feet sweat as you walk to the stand and then your feet will get cold. Great boots. I have a pair of the old plain green ones I bought back in the 90's that I have worn the tread off. I use these for scounting and hanging stands. I bought a new pair five years ago that are still going strong.

 

Always go larger. I am a 10 1/2 and always have to get an 11 and I wear nothing but lacrosse boots. Never go smaller or same size cause as you said with heavy socks on they will be extremely tight and then your feet will get extremely cold.