Spine Question??

Joined
Nov 8, 2021
Messages
96
Location
Minnesota
Hello, I am getting some new easton axis 5mm shafts. And I am trying to determine what spine I need. Here is the specs of how the arrow is going to be built.
- 27in Carbon to Carbon or 27 3/8 from Throat of Nock
- 28.5in Draw Length
- 70lbs
- 175 Grains up front - 50 gr insert, 25gr iron will impact collar, 100 gr head

I am pretty confident that I need a 300 spine arrow, but wanted to double check. Any help is appreciated, Thanks!!
 
Joined
Jun 21, 2019
Messages
2,228
Location
Missouri
300 should be about perfect. Below is the output from OT2Go assuming a pretty typical modern compound bow (340 fps IBO, 6" brace height, 80% let off).
Screenshot_20211214-093748_qSpine.jpg
 
Joined
Jul 27, 2017
Messages
691
Ya I would start with it around 29” and cut down the back end of it comes out weak when you tune. If you don’t get into tuning that much that just go for it, should be close.
 
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