I don't know of any websites that are that accurate, but I know of some software that is fairly accurate. Either OnTarget2 or TAP. Both have downloadable free trials if you want to test them out. And eastons arrow selection software is fairly decent and is free. You are just limited to easton arrows, or arrows they own. It works fairly well, but isn't as detailed as the other two. If you know how fast your bow will shoot a particular arrow you can put it in either of the programs and they are pretty acurate at determining the correct spine for your set up. You may still have to do some fine tuning though.

Online calculators and charts are very generic and don't ask for much information. There are many things in a set up that effect what spine you want. Depending on your set up you might end up getting arrows that don't work for you, even if the chart said they would. You wouldn't beleive the amount of people I have met both on person and on the net that got arrows using a simple chart and ended up with the wrong arrows and there was no way to correct it short of getting different arrows. Some arrow charts only ask for arrow length and draw weight, that's it! That is no where near enough information to be accurate at determining what arrow you need. Especially with how much the effeciency of bows have improved in the past 5 or 6 years.

Sure you can fine tune them once you get them, but changing tip weight doesn't change your spine a whole lot either way. I mean if you are a whole spine selection off no tip weight change is going to correct that. At least not one that will give you a good balance for specs. And you can only trim your arrows so much before they are unusable, and I know of no way to make them longer if they need to be.

I will agree with Greg, nothing is perfect, every set up is different. However you want to be as close as you can get to start with. And if you have to go in one direction or the other, slightly stiff is usually easier to tune for. I wouldn't suggest going a spine selection or two stiff though just to be safe. Too many people get locked into having something an exact way. They have to have an arrow X amount of length, or have to draw X amount of draw weight. Or they have to have X amount of tip weight. Being unflexable like that makes it hard to get the best spine you can.

Your best bet when setting a bow up is to set it to the middle of the draw weight range, and get arrows a bit long. This way if you have to make adjustments you have the extra leeway. If your bow is maxed out and you get arrows that barely work for length you sort of screw yourself if you need to make an adjustment. If they are too stiff and going up in tip weight doesn't help you will have to get new arrows, because your weight is already maxed out, and your other option is longer arrows. If they are too weak and lighter tips don't work for you your other option is turning the bow down. If you don't want to do that I guess you are getting different arrows again. Or if your bow was at the bottom of the weight range you would have the same problem.

That is one of the reason bows have adjustable limbs, so you can tune them better. Just no one wants to do it because they are so macho their bow HAS to be maxed out.

Be carefull with paper tuning as well. I have gotten severely weak arrows to shoot bullet holes and group well. Just to a different impact point as stiffer arrows is all. And I am sure a broad head would have went crazy on them. They shot thru paper just fine though. Also paper tuning, or any type of tuning for that matter is very dependant on form. If you don't have consistant form or grip tuning will be a night mare. You can't tune any better than you can shoot.

If you are going to hunt I suggest broad head tuning since that is your ultimate goal.

Paul