Help! I have two arrows setup identical, they weigh within 3 grains of each other. They are Easton GG 2016's cut to 29 inches, 3-5 inch feather fletches, 28 inch carbon weight tube inserts that are 5 gpi. They are tipped with 130 grain STOS heads and 45 grain screw in adaptors. Total arrow weight is 661 grains. Broadheads are aligned identical on each arrow. My problem is, one flies like a dart and the other one flies like a banana. Both spin test perfect. What gives?

Nock on crooked?

What is your bow poundage? Sounds like you are extremely weak. Or does the carbon stiffen them up? Ussually loading up your arrows weakens them. You need to try more than two arrows. How do you know which one is acting normally when you only test 2?

Bow is 51 @ 28 and I draw 28. I am getting ready to deploy to Mississippi for training for 5 months and 2 arrows is all I have had time to setup. I have been shooting 2016 cut to 29 inches with a a range of different weight field tips. They all fly good, I have even been shooting a couple with only 2 fletches on them and can hit water balloons at 18 yards! I am new to the trad thing and have been getting somewhat frustrated with the tuning and hunting arrow setup. Anymore advice is welcome. I am shooting a 64" longbow that is 51#@28" and like I said before I draw 28".
Thanks.

If the same arrow always flys like a banana?  When you spin test them do you also look at the spin of the nock?  I like to build wood arrows and sometimes I don't always get the nock on straight.  A crooked nock might would cause erradic flight.  Next thing to do is swap point with the good arrow and see if it gets better or worse.

Are all three of the feathers on the bad flying arrow from the same wing?     Pat

Fletching from different wings, a bent shaft or a bad nock.

Probably the fletching or the nock.

Get rid of the weight tubes!!