ORIGINAL: bigcountry
so does it sound logical to keep your arrows long and cut down as you need more spine?
That would depend on your draw length and draw weight.... Just be sure to have already calculated about what spine you "think" you will need at a given draw.... Then leaving a few incheslong won't hurt you..... You must keep in mind thata longer shaft will act weaker and a shorter shaft will act stiffer.....
For instance... Wood spines are measured at 26 inches...... So, a spine of 45 would act weaker at a length of 30 inches.... And act stiffer at less than 26...... I shoot 28 inch arrows, so when making my shafts I usually use a spine that is 5lbs heavier than I will need. That way, the extra two inches will offset the heavier spine....
Now, that's the way I understand spine and it seems to work for me.... Some of these other guys have years or decades more experience than me. Hopefully they will tune in and add some pointers......