Again I'm going to disagree. The programs give you numbers but in no way do they tell the person HOW to get those numbers into an arrow. They give you the "perfect" spine number in between what is actually produced by the arrow companies-------so say I'm between a 400 and a340 spine and I want that perfect number the program come sup with then tell me how to achieve that number just don't give it to me.
Not coming down on the purpose but these programs are far from perfect and tend to give the "average" archer more problems that don't effect them than they need.
Now to the reason why using one program over another and getting different results. Bottom line two different trains of thoughts------you only get out what a human person perceives and puts into the program. So technically it is someones opinion-----same as the charts from the people that design the arrows for the masses.
Not the case at all. I find the programs very close between one another and with first hand testing over the past 8 years with them, I find them far more accurate than a spine chart.
The reason, spine charts do not account for the most important part, dynamic spine. They do to a degree, but know where near what the programs offer.
If you want a better start to the foundation of your tuning process I would highly suggest an archery program.
I mean no disrespect but if I go into a archery shop and see them look on the back of a box for advise to give some one, this is the first sign of the knowledge of that shop IMO. Not only lack of knowledge but I have an idea they would be pushed out the door without the best tune for their set up.
These same shops will have their customers shoot through paper to achieve a bullet hole regardless how their form is. One bullet hole in paper at one distance does not mean you are tuned.
I see this all the time.