Question about arrow spine...

[Ifrit617]

I know that most arrow shafts are spined at 28" when measured. I also know that arrows gain about 5 pounds of spine weight when shortened by one inch.

Now lets say I make an arrow that is 26" to the base of the point from a shaft spined 35#. Since the shaft length is still 27" with one inch inside the point, would the spine of the arrow be 45# (due to the 26" length to the base of the point) or would it be 40# (due to the total 27" long shaft length)? Thinking about it is making my head spin. 

So what would the spine be? Any help would be great.

Thanks.

Jon

[Fred Arnold]

35#'@28 would be approximately  45#@26 from back of the point to groove of the nock (but) if you inserted a trade point, nail, or stone point up the shaft those figures may very well change slightly.