I beleive that part of the idea of left versus right is that most archers are right handed. When left helical feathers leave the bow supposedly theyspin away from the bow and not into it. I have shot both and if thebow is tuned it doesn't seem to matter.
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Keep your powder, martinis, and trout flies dry!
The main reason is whether to person is shooting off his knuckle or not. One way will dig in and cut and the other will not. If you shoot off the shelf it will not matter much.
Personally though, I use right wing mainly becuase it matches the bevel of my grizzly broadhead. I don't want the arrow spinning opposite of the way the bevel wants to cut.
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"I do not Hunt animals to Kill them. I kill animals because I Hunt." Roger Rothhaar
It really does not matter unless you want a certain helical. Also is you are using single bevel broadheads it will matter. Was an old understanding that right handed shooters should shoot left and right left, the way the bows was built. but now a days doesn't matter.