larger shaft diamater compared to small diamater of the same wgt.
 

i have to type of arrows i shoot and they both weigh the same in grns. gt 5575 xt at 26 1/2 at 368 grns compared to easton epic shaft 400 at 27 in both with 4in vanes.i chronoed both shafts tonight the gts showed 270 consistently and the epics showed 275 consistently. both have the same nocks.does the smaller diamater shafts create less wind resistence

RE: larger shaft diamater compared to small diamater of the same wgt.
 

Wind resistance won't make that big of a difference. I'd say the faster shaft is more properly spined for your set up than the other one and is able to better utilize the energy from the bow. But that's just a guess.

RE: larger shaft diamater compared to small diamater of the same wgt.
 

How sure are you that these two arrows weigh the exact same? I find it hard to believe that your getting 5 fps difference with two arrows that weigh exactly the same. I've played with many arrows through a chrono and the same weight carbon vs aluminum of different diameters shoot the same fps...

Am I to assume you scaled these two arrows or are you assuming they weigh the same by some other means? I'm just trying to get info to reason your hypothesis with more information....any info you can give would be appreciated..

RE: larger shaft diamater compared to small diamater of the same wgt.
 

Usually the same weight arrows will result in the same speed at the bow.


I suspect there are tuning issues with the slower one.


Downrange a smaller arrow will show a slight increase in speed.