I also agreed with Gerald and will try to expand on it.
All bucks have a potential that is likely fixed by the end of there first year of life. By potential, I mean the size of there antlers at age six. Once a deer reaches age 6 antler improvement/regression is minimal until the buck is on his way out and those bucks rarely live another year. If you were to graph the six year old antler potential of all two year old bucks you are going to get a nice bell curve. Were I live, I think that the peak of the curve is some were in the 160's B&C. Say 165 for the math. This means that for every young buck that at age 6 will score over 180 there is another buck that will not break 150. This does not mean that if you were to score all the 6 year old deer taken in MT in a year the average score would be 165. Bucks at the top of the bell curve are will often score better than 165 at age three, bucks at the bottom of the bell curve are just never very big.
Montana has a long season that runs the entire rut and then some. This allows hunters in Montana to be very selective and many of us of course select the buck with the best antlers we can find. A buck with the potential to grow 200 inch antler is passed by almost no one starting at age 3 and the counter part on the bell curve that will never grow antlers better than 130 is likely to be let go by many even when he is old. In Montana with the long rut season this means that very few bucks with top end potential ever get past 4 years old and most of the top end buck that do are most likely spending most of there time in places that are off limits.
Trap, I think you may be right that other places my have a bit better genetics, As in those places bell cure peaks at most 5 inches better than Montana's. I would caution you in that you can not compare older bucks taken of the same age from different places and make the definitive claim the place with the bigger deer has better genetics. Better genetics may be the reason, but it could also be that the hunters in the place with the smaller bucks are just better at selecting out the top end bucks at a younger age. In Montana's case I lean more towards we are good at selecting. Montana has good genetics, maybe not quite as good as Colorado, but far better potential than the type of deer we are currently taking. The buck below has the best potential of any buck I have ever seen. He is four years old in the picture and grosses 194. As a three year old he was likely better than 180 (antlers are broken up so I can not be sure) He did not make five, If he had lived to six I am confident he would have been well
over two hundred.
I agree with you too

I have just been having that genetics argument in my head for 30 years. Ha ha. I’m on the same page with most posters just a question on genetics or some other factors possibly that I wanted to put out there. Really good feedback, I appreciate it. Makes sense that if superior genetics get shot as 3 max 4 year olds hunters could be selecting the best genetics OUT of the pool. I think that’s what you were saying. Thanks for the information that might be the answer to my question