>>693056The idea is that your arrows flex as they are shot and to shoot accurately you need to get the amount of flex right. Your starting point is static spine (i.e. 340, 400, 500 etc) and from there longer arrows flex more, shorter arrows flex less and more point weight creates more flex. In terms of both you and your bow, longer draw length and higher draw weight will make an arrow flex more.
For you, you are probably overspined (your arrows are not flexing enough) if you are shooting a 340 spine with 100 grain points. If you're right handed, this probably means your arrows are flying left or hitting with a leftward slant because they're not bending around your bow enough to recover and fly straight forward. If you were underspined, it would be the same but off to the right as your arrows would be bending around the bow too much.
The way to do fix this without buying new shafts is to try much heavier points (we're talking point and insert weight = 200+ grains) to create more flex. Also, get measured for draw length - it's important for all of this. How tall are you? (it's a rough guide for DL).
Vanes are not helping you here. They're hitting the shelf of your bow as you shoot and deflecting off, which is throwing off your shots. Feathers compress and don't interfere with your shot. If you want to shoot vanes, put a flipper rest on there, but if you want to shoot off the shelf, get your envys re-fletched with feathers.
The ideal solution is to get your draw length measured and then plan an arrow with that spine calculator I mentioned and then buy/build your arrows like that. To make a 340 bend enough out of a 45# bow will, as I said, need a ton of point weight which will make a slow, quiet, heavy, high FOC arrow - not a bad hunting arrow, but it might not be what you want. Better to purpose-build and get it exactly right rather than just wrangle what you've got.
