I'm at home and do not have access to excel could someone runs some #'s for me? I have a 55# @29.5 Centaur longbow and want to shoot a 30.5",  9 gpp arrow with about 20-22% FOC out of it what arrow does Stu recommend for starters? I'm currently shooting 340 spine GT Expeditions 7595 (black) 30.5" 520 grains total with 200 up front and they shoot good but do seem to shoot just to the right a little.  I want to use as much FOC up front but without going extremely heavy (staying in the 9-10 gpp range), thanks for your help ahead of time    Other info that you need 1/16 of center shot,  anything else?

...and tell what/who the Stu and excell knowledge is/means. I'm out of touch evidently...thanks.

I rushed through this but right now you look overspined and need weight added.

http://www.heilakka.com/stumiller/

I found it...

Going to 55/75 with 12 strand FF heres one.




With 14 strand FF



Ballpark figures and I'm sure I messed something up.

Hey Bud B. i'm sorry but the rated draw would be 50#@28 and i shoot 3 4" feathers.  String is a 8 strand D97.

QuoteOriginally posted by Woodduck:
...and tell what/who the Stu and excell knowledge is/means. I'm out of touch evidently...thanks.

No, you're in touch with your bow and arrive at the same results emperically and outdoors where it counts.    

Woodduck, and Stumpkiller lol yea,yea, yea these new fangle comp.put.ters sure mess up a good object lesson!  Hey it's raining cat and dogs here today and I don't have the mula to spend experimenting with different shaft etc... so this the best way to get a good start.

Bump up to 225grains or 250grains up front and see how they do. To test this is about $10 for a few heavier fieldpoints. I don't see that a few more grains/lb would make any difference at hunting distances.250 grains would give you 10.36 grains/lbs. 20-22% FOC can not be reached with the next weaker shaft, see calculation examples. It only costs you money for new shafts,inserts etc. Carbon still has the disadvantage of only having a few spinegroups available. Often, the needed spine for a setup is just between 2 groups. One would be too weak, the other too stiff. Part of it. Aluminum or wood do not have those problems....

I understand.  I've priced carbons and to buy the wrong spine would be a bitter pill to swallow.  Stu Miller deserves a big thanks for making selection more understandable.  

One reason I never got into carbons was I had no 'splanation so I've stuck to cedar; now fir.  My ways are set and now it's a matter of principle!  (I've never used an ATM or owned an automatic car, either - gotta be stubborn about something).

Thanks everyone!  The shaft I now have work just wondering if I could get more EFOC without extreme heavy wt.

Thanks everyone!  The shaft I now have work just wondering if I could get more EFOC without extreme heavy wt.

In order to get EFOC, you need to add weight to the tip. In order to stay the same weight, you will need a lighter and stiffer shaft. And you already shoot a "lightweight shaft" for the stiffness. All Easton shafts will stay at the same weight and the other manufacturers won't be different.