Ive always used 3, 5 inch shield cut feathers on my arrows...left helical.  I am a big 2 blade fan and like to shoot the stos,  zwickey and simmons....as they fly great for me.  As of late,  Ive been wanting to try some 4 fletch...just got the nock receivers (4@90) for my JoJan.  My question is this:  using 4 fletchings instead of 3,  can I get away with using a bit shorter fletch?  Say 4, 4inchers?  Or should I stick with the 5 inch?  To make it more interesting,  Im thinking of trying parabolic!  So using 4 fletch,  what would be a better formula:  4, 4 inch shields,  4, 4inch parabolic or 4, 5 inch parabolic?  What do ya think?

I really like 4-5" parabolic, however the 4-4" parabolic seem to shoot the same with field points.

There is a definate recipe for stabalizing a broadhead with all fletching patterns.  I would start by perusing the 4 pages of 4 fletch postings using the search tool up top for PowWow forum.  

~CB

4 4" low profile parobolic will give u 16 inches of stablelization,vs your 15 inches of your shields.I f u r tuned good that makes little difference as how they shud fly, with your 2 blades and 4 fletch u knock n go,no worry about cock feather in out etc,i find parabolics quieter in flight also,experiment n have fun

Exact size and fletch I'll be using on some new shafts........so no experience as yet, but, I do have 4x5" fletch which DO fly nice. I expect the new sizes to do well also.

Folks talk of 16"(4-4") vs 15" (3-5") but I am guessing that the 5" fletch have more actual surface area because they are full size (height) for more of the total length.

That said, I have had no trouble with 4-4" fletch and broadheads.

ChuckC

I am also a 4x4 user. Seems to Do well with the 2 blades I shoot. 200 gr tusker Aztec, 175 grain vpa  and 165 grain zwickey no mercy. Parabolic seem quieter than shield to me.

What Chuck C said    X2   regarding surface area. I think the common #feathers x feather length is misleading to determine the amount of guidance you are getting.

I have been shooting 4x4" parabolics with the 60x120 pattern and really like them. I think the shorter feathers wear better and last longer than the longer feathers.

But the best way to tell is to fletch up some arrows with the fletching patterns that you want to compare and find a good broadhead target (or dirt bank or sand pit) and shoot some big broadheads. If its a windy day, that's even better.
You will soon know what's working and what isn't under FIELD conditions. Maybe even wet the feathers a little!

Good luck

I have switched between 3 and 4 fletch over the years.  I have most recently been shooting 4-4" parabolic feathers with a 240 gn Bowyer Brown bear broadhead on Arrow Dynamics Traditional shafts.  Just this year, I have been experimenting with 4-3" parabolics (to reduce, theoretically, arrow noise in flight) and they seem to fly as well as the 4" parabolic. I don't yet know what I am going to hunt with this fall-but will probably go with the 4" due to habit and the experience that they will fly well under all conditions (old habits are hard to break!).

I burn my own fletching so I can shoot any length I want... 4.75 for example. Who says you have to add or subtract a full inch?

If you use the same cut fletch....and same height fletch you wont be able to shoot the difference....but your arrow will be more stable with the 5" in more rigorous scenarios in the fields, climate...whether....environment....body/shot position etc...

   

Well,  good points to ponder.....I think Im going to give 4 4's a try in parabolic.  Thanks all for the input and advice!