hey guys im from down under (australia) im shooting a samick slb AFB 66 pounds at my draw 30inchs im shooting easton powerflights with 4 inch feathers and 125 grian tips i started off with 340 spine but found they smacked the back of my shelf then i tried the 400 spine still the same now i got me 500 spine problem solved but i hear every one saying you should shoot on the stiff side anyone found this not to work for them

shoot whatever arrow spine works best for you - that is, whatever arrow renders excellent arrow flight.  if it works well, not much else matters.  

fwiw, i use 29.25" 500 carbons w/350 up front, out of 55# stick bows.  

Take a bare shaft and shoot it. it should be just a tad stiff. If your right handed, nock left.

The flight of the arrow will tell you what spine you need. Every bow seems to want something a little different. You are getting good flight, and that is what matters.

For reference: One of my bows is 51# at 29" recurve --- I get the best flight from a 29.5" 400 spine with a 26 gr glue-on-glue-in insert, 160 gr point, 8" wrap, aluminum nock adapter, Bohning classic nock, and 3 5" feathers. That is a pretty stiff arrow, but with an SBD six-strand FF string, it is what the bow wants.

The time and effort it takes to experiment is well worth it for the confirmed good results.

Have fun.
Joe

QuoteOriginally posted by Craig:
Take a bare shaft and shoot it. it should be just a tad stiff. If your right handed, nock left.

I believe that is backwards.  If a right handed shooter shoots a bare shaft and the nock is left, the shaft is slightly soft, which is what you want.

but with 66# and a powerflight with only 125 grain tips in my opinion youre arrow is way to light for the bow!
Youre arrows should be between 550 and 750 grain to be in the 8-12 grain per pound range. Though 10 grain per pound and up would be better to keep the bow silent and give the arrow a good punch.

Perhaps take those 340s and load em up with front weight till they fly good.
Just a suggestion, youd be surprised how much more stable and silent the bow gets and how much better penetration would be.

I too can't shoot anything stiffer than a 500, even with 300gr. up front. Watching multiple shooting come through camp last year I realized that the majority were shooting too stiff of an arrow.

I shoot 600  spine shafts from an RD longbow - 55 lbs @ 30".  I have 400 grains up front.   Everyone tells me they are to light of a spine.   bare shaft to fletched shaft tuning tells me otherwise.   Most carbon shooters I have worked with find their arrows are overspined when they bare shaft to fletched shaft tune.

I shoot 500s out of my 60lb no problems.

QuoteOriginally posted by saumensch:
but with 66# and a powerflight with only 125 grain tips in my opinion youre arrow is way to light for the bow!

X2, put some point weight on a 340 shaft.  Start full length and keep adding weight until you get it. Then fine tune for length.

I'm shooting easton 500's out of a 50# @ 28" recurve, so i'd assume you would be underspined for that bow??? The arrows are cut to 29" and I draw 28" with 125 (maybe 150?) grains up front

Listen, I agree you probably need to increase some weight on the arrow.  530 grain minmium.  You do not have to have 12 gpp pound to get adequate punch, And if you have the right string and brace, it won't be to loud either.  But that arrow weighing less than 530 grains will more than likely void the warranty on that bow.  God Bless

my widow 66 @29 and my 500 fly awsome out of it

thanks for all help guys it was real helpful learnd a thing or two