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Q If I fletch my arrows straight rather than offset will I leave a bit more energy in the arrow? Seems like there must be some sort of trade-off. Am I missing something?

A While manufacturers put effort into making high quality arrows that are straight, they are not ‘perfectly straight’. Careful testing with my shooting machine shows that if we ensure that the arrows spin about their longitudinal axis the groups will be tighter and we will score more. We can do this by placing the fletches at a small angle to the shaft - 1 or 2 degrees is quite sufficient and in any case is about as much as you can get on a small diameter shaft such as a Protour.

It does take a small amount of energy to get the arrows spinning, and that energy comes by slightly decreasing the arrow’s speed. However the decrease is actually very small - only 1 or 2 ft/sec typically. So, is there a trade-off? Yes, you get smaller groups and a higher score at the cost of a very small amount of arrow speed. Is it worth it? Absolutely.

THE LARGEST CONTRIBUTION COMES FROM AERODYNAMIC LIFT, NOT DRAG.

One misconception I regularly hear is that with the vanes at an angle the drag will be higher. However that is not the case. Once the arrow is up to its stable spin rate (which happens within about 10 m from the bow) the vanes are effectively edge on to the air flow and their drag is no different to that for an arrow without angled vanes which is not spinning.