It's judt a supposition....but as the terminal velocity of a goose feather, which is what I've used in the past, is slower than that of a raptor, I'm wondering if I should re work my arrows with raptor feathers? any thoughts before a great undertaking would be welcomed

Illegal where? Don't you live in australia? Anyway I think english is right, it is the area of the feather not the bird it came from. Unless raptor feathers are much lighter per square cm than goose feathers. Are they?

Weeelll, here in Australia we get a lot of wedge tailed eagles that get hit in road traffic accidents...find 'em lying by the roadside all the time...and I was just wondering if it would make any difference in speed, flight and so on...might sound different too....just a thought really...

I'd love to nip down to the local pond and scavenge a few wild goose feathers but unfortunately that would involve driving to Adelaide....like hopping in the car and going from London to Moscow....so picking a few feathers from some poor roadkill victim just seems ok to me...over here it is illegal to trap, poison, kill wedge tails and so far no one I've spoken too knows if it's illegal to use parts of an already dead one....sentimentally I can see peoples points but I'm just thinking that if I have a ready supply of something and I'm not killing anything to get it, what is wrong with it...my query originally was as to wether they'd be any good for the task....but I seem to have opened a pandora's box so nuff said....

Absolutely...and thanks by the way...How did you go with the black bears ? I've been thinking of going north for scrub bulls....or west for pigs...either way it's expensive....s'posed to be some pigs round here but I've not seen any evidence yet.....do you know about fletching shapes ?  seen all types but not tried them...is their some arcane mystery behind them....tried to cut some with a hot knife but whoa it's hard to get symmetry (can't spell either )....

I don't see a problem with it, so long as it's not illegal, you aren't harming a live bird, and you make some gorgeous arrows.  They have to be really pretty.  Make the arrows only when you are feeling good, use some good quality shafts, use either homemade bindings or some good quality silk - don't squander the flights, man!
 Symmetry is the aim... there are some many fletching styles.  If you want symmetry easily, then glue and lash the feathers on and cut with scissors.  It's not totally paleo, but...  Anyways, they are as you say many styles.  Choose one that looks nice - there is no secret, just cut to the shape you see.  Practise on some rubbish feathers before you go right in there with your nice ones.  Splitting feathers for flights is an art, so get that right too.  It's not difficult at all, you just need the knack.