445, In the March 2003 issue of Peterson' s Bowhunting Magazine there is a great article called MAXIMUM FLIGHT (How Fletching Styles Influence Arrow Performance). The article talks about vanes or feathers,straight versus helical,clearing the arrow rest, the test, the results and finally the Broadheads.There is alot of good info to list but he does mention what you are experiencing. He says that at 20 yards the broadheads flew the same as the field points. At 40 yds. the shooting machine still shot the arrows to the center, shot after shot, with great consistency.When he shot the arrows , at 40 yards the point of impact changed, he goes in detail and talks about the fletching 3" , 4" ,5" feathers and vanes. Hope you can get the magazine.