Remember that adding weight to the tip, as in the heavier point weight, will break the spine down faster with less weight added than adding weight inside the arrow shaft. If you think about it, a longer piece of stiff metal INSIDE the arrow will STIFFEN the tip of the arrow unless the arrow is long enough that the arrow insert is PAST the front of the riser when at full draw. Adding weight at the point, which naturally hangs out past the riser when at full draw, weakens the spine much better than adding insert weight. Now, if you want to use the insert weight, you will need to experiment to see how much weight you will need up front to get the results you want. For example, I like heavy arrows so I went up one spine in carbon arrows, then broke that spine down by adding 100 grain brass inserts inside the shaft and bare shaft tuned the bow. It wanted 235 grain tips AND the 100 grain brass inserts. You would think this is too much weight up front if you did the simplified approach of adding insert weight and point weight to come up with a desired point weight. It doesn't work out that way. Another way to look at it is if you want to make a hollow tube stronger, you fill it will a stiff material and the 'flex' is dramatically reduced. Same thing happens with the LONGER brass insert. Hope this makes some sense. Frustrated me too when I first switched to carbon arrows. Steve