Honestly? Base to tips mid August. I feel and have studied that circumfrences, mass, and density come in play layer ? That's the hidden secret. Circumfrences/mass is fullfilled all the way to a few days before the velvet dries and begins to loosten. Density? Also a form of weight. I am a firm believer that a buck's internal antler density is not complete till the hormones kick in about early October. That's my study. Take it how you like it. I have studied all forms of antler growth and the strongest heaviest filled out finalized package is early october. Nice and polished up too.
Runnin'em down like a dog has always worked best for me.