Frankly, I'm really compromising my beliefs a great deal by not calling for 450 or 500 grains. It's only in deferrence to the light arrow addicts that I am willing to accept as low as 400 grains.
Arthur, in my opinon you're fighting an uphill battle here. I frequently get into discussions at the local archery shop, about all the benefits of the heavy arrows and 90% of these guys stare at me like I just told them the state banned bowhunting with anything less than 6 lb arrows. These guys would think that to get to 500 grains, you'd have to dip the arrows in lead. I think part of the problem is the number 500 - they must think it equates to pounds or something similar. They don't have a clue that there are 15.4 grains in a gram and that there are 28.3 grams in an ounce.
If states made new laws that stated arrows had to be no less than one ounce in weight, they'd probably not resist it as much. Imagine, archery might become less like shooting a gun and more like, well you know - shooting a bow and arrow.