Spine Calculator vs. the hard facts..

[Phil Magistro]

I really like Stu's calculator.  It's not perfect but it gets you close.  I have a Dalaa with Winex limbs shooting around 45#.  I'm using a cushion plunger and a T-300 rest.  I have several others bows in this weight that shoot GoldTip 3555 cut 29 with a 125 grain point.  This bow can shoot them but it's not the best arrow.  It likes GoldtTip 5575s with a 145 grain point and 66 extra grains of weight in the front.  According to Stu's calculator both of these are slightly higher dynamic spine than the bow should shoot.

[Nativestranger]

For me Stu DSC tend to recommend weaker spine than reality. I have some full length gt 1535 with 100grain tip that DSC says should fly well from my 42# recurve. But the bareshafts group far to the left (leftie) and fletched shafts fishtail like crazy. Put on my 30# limbs and they group in the middle and fly like darts.

[Brock]

that is why on Stu's calculator....they have the option to input the archers FORM points....as if you find an arrow combination that flies perfect and goes against the chart...you add or subtract points until it works out.  Then that becomes your NEW FORM factor that makes it unique to you and will apply to all future searches for arrow and bow compatibility.  We are all different so it is really a place to start if you have no idea...

good luck

[FrankM]

I've tried Stu's Calc since I had to learn on my own, with help here. Eventually, I abandoned it. I tried a bunch of different ways to tune it and finally was able to tune Gold Trip trads 35/55 30" with 100 gr. inserts and 145 grain field tips and broadheads. My bow is a #50 Jaguar that I've shot for a few years. Anyway, the broadheads and field points hit the same place. My Napper rest is set to about 1/8", almost centershot. The form factor of Stu's calc will not allow me to match the arrows to the bow. So, I play with it, but it hasn't done me much good.

[Hoyt]

I go with the hard facts..like seeing is believing. I do use the calculator to check things out, but my hunting setup is stiffer than the calculator calls for.

[dragonheart]

Just food for thought.  You have to put in accurate data into each one of the variables.  The other thing is bow weight and draw length.  I always weigh my bows at my draw length.  Never trust what is marked on the bow.  I measure draw-length, while actually shooting the bow, not just drawing the bow back.  This effects the poundage if you think you are pulling a 60# bow at 28", but in reality you are pulling 27", well now you have less bow weight and bad calculations.  Many people are surprised at their drawlength when they measure it when actually shooting.  Actual data is the key to the calculator.  I find it a helpful tool.