For the las 2 years I have shot 5575s out of a 02 bowtech patriot sc at 71lbs, 29" draw with 100g broad heads. The set up is shooting 278fps. The bow shoots well, and out to 50 yards, I can't discern a difference between field tips and the broadheads (snypers and slick tricks) for accuracy. I recently picked up a "back up" bow with the hope that it would shoot the same arrows. It is a 03 bowtech patriot sc at 74lbs with 29" draw. The bow shoots well, although surprisingly, noticably slower than the 02 model shooting the same arrows (I haven't chronographed the new bow but I can see an identifiable trajectory differece between the bows). I've read that gold tip chart are questionable, particularly with high energy sc bows. I've also read that if close to the high end of the 5575 chart, to go up a size. Bowtech advises for top efficiency, to shoot the bows maxed out so I'm not inclined to back of on the limbs of the already slower 03. Do I need to switch up to the 7595s for the 03 even though it is not shooting as fast? Does draw weight impact spine requirements in a way that excludes actual velocity from the equation? I would assume that all things being equal, more draw weight would necessarily mean more velocity. Am I missing something here? Does anyone have an idea why a bow that is 3lbs heavier shooting the same arrow is going noticably slower? By the way, the bows are set up the same with the exception of the factory hush kit that came on the 03. Is it possible that the addition of factory string silencers could have such a noticable velocity difference? It is hard for me to imagine that the factory hush kit would slow it down to the point where the shooter can see a noticable difference in arrow flight. Are the manufacturing tolerances such that the same bow set up the same can shoot that differently? Any thoughts or suggestions? Bowtech's online support person didn't seem to have any suggestions/answers. By the way, did I say I love the way these things shoot?