Impossible to know. A couple years ago, at the big buck contest in beulah, a vast majority of the big mule deer on display had two things in common. 1. they were taken on private land ( I knew this because I either knew the folks that killed it or I saw a gratis tag on the antler). 2 They were taken with a rifle. Again, like your example, very anecdotal. But I would imagine there is some year to year variability. In general, I think anyone would tell you your odds of killing a big buck are better in November for most people (especially ND Road hunters). Considering we have over 6,000 rifle hunters in the badlands over our 16.5 day rifle season, with a nearly 80% success rate, I find it hard to believe that bow hunters have more of an impact on populations and antler size than rifle hunters.