From what I've read over the years (and personally observed as well) whitetail deer antlers reach approximately 90% of their full growth by
July 15th over most of their range. Nutrition, environment (particularly drought) can affect this. In a drought stricken area where feed/nutrition is affected antler growth will slow down considerably. What you see by July 4th as far as antler develpment will be pretty much what you see when they shed the velvet...They may add a little tine length and main beam length, but not much else. Spread, number of points, and mass are set by July 4th.