Very true about shortened arrows and increased spine, Pat B. So far, don't know why, I've been able to shoot arrows after I've broken tips off, re-tapered, and re-tipped using the same weight tip (100 grain). I don't think I would have sucess in this if I had to re-tip/re-taper an arrow which had previously been re-tapered/re-tipped. With the 3/4" long taper that would equate to a 7 1/2 # increase in spine.