Many theories on antler drop.....from my own experience and thoughts several variables...some bulls simply drop earlier than others...I collected one bull in 3 consecutive years and even as an avg 6 he dropped in March which was odd for his size....did he drop because he was an early calf, possibly....he also would drop his antlers very close together which for anyone who shed hunts you know this is not common and a pleasant surprise. Some theorize new green growth does something after a winter of just filling the belly and you get some nutrients and off they come. Many things to consider and that being said is that the only constant is learn your area and each year that area some will start to drop regardless of anything else, just some drop early, some don't, others drop very close to each other and others will pack one for days irregardless of size.