If any of ya'll all are the "why buy it if you can make it" kind of guy like I am (i.e. too poor, tight, and/or proud just to buy it), then this might float your boat. I had some old arrow shafts laying around that I wanted to make up for my fall hunting arrows (heaven forbid I should buy new shafts!) Well, they were spined just a touch heavy and came in a little light in weight (about 60 grains light). I could have just bought heavier points, but then I would have had to buy heavier points
So, I added a 1 1/4" piece of brass tubing just behind each broadhead, secured it with hot melt, cut the shine with steel wood, and VIOLA! 60 grain increase in total arrow weight and spine problem fixed. They fly true and that annoying bit of handshock is gone. Not the best way or place to increase total arrow weight, but its get the job done...country boy style!
I've used brass tubing to make blunts and such in the past, and the only downside is that you create a rather long rigid section at the end of the arrow that can snap off if you shank or deflect an arrow. By hey, that gives me a reason to make more, which is the whole point in the first place!