It would appear that gun drills are generally the tool of choice for boring flute and whistle tubes, but how about parabolic flute drills?
It seems to me that the parabolic flute drills would do a much better job of clearing the chips from the bore, but that’s just a theory.
I’m hoping someone with experience in the matter will confirm or refute this theory… I’d hate to purchase an expensive drill bit that will end up just collecting dust in a drawer.
I know that with wood, compressed air is often pumped through the coolant hole in a gun drill to blow out the chips as well as help reduce the heat inside the bore… but I doubt this method would work as well with acetal.
HA HA HA! When I read your post, I thought that “parabolic flute drill” was some type of drill specifically used for making flutes 
If you have deep holes to drill and need very good accuracy, a gun drill is the way to go. Once you bore a nice accurate starter hole about 1/2" deep, the gundill is self guiding and drills a perfect, blind hole with very little drift if any. I ordered mine for www.danjon.com and have been very happy with it. They put it on a #1 Mose taper to fit the tailstock of my lathe-- the wood/plastic spins and the drill is stationary. There is a compressed air adapter which I connect to my compressor and this works like a charm. Wood comes out as a fine dust( which would go everywhere, so I make a sort of tent out of clear vinyl for this operation which confines the dust to the top of my workbench). Delrin works too-- the drill cuts it into ribbons which come spitting out in the form of little rolled up pellets. When drilling wood I apply steady pressure to the tailstock, but for acetal I push the tailstock in a pulsing fashion which keeps the little pellets from lodging in the hole being drilled.
Contact Danjon and ask for George Metz. He’ll discuss your lathe setup and your needs and they can design exactlywhat you need. About 3 years ago, my drill cost about $130, plus I had to buy a Sears compressor for another $100ish, but it’s been worth every penny.
Hee hee, I thought some NRA nutter with an interest in parades had drifted here from the poststructural pub!
Yes, I don’t have a gun drill. (I wish I did at time) but I have seen Dave Copley’s shop and that, I would recommend a gun drill.
BTW - Paul, I have done the same thing for boring acetal. I go in a bit and then bring the tool back out to clear the little strips that build up around the tool.
With the compressed air feed to the gundrill I don’t really have to bring the tool out: I just pull it back a tiny bit so it stops cutting and the air flow shoots that little rolled up wad of acetal out with a cute little “pop”