I thought North American whitetail magazine had a article of a buck from canada that was more than 500 pounds live weight. The article showed a pic of the deer and it like a steer laying in the field. If I remember right it only had a big six point rack but the mass was unbelievable.

While I was trying to find the article I cam across this:

In 1926, Carl J. Lenander, Jr. took a Whitetailed buck near Tofte, MN, that was estimated at 511 pounds live weight.

Now that is a big deer if true.
Dink