rachnid, I know that you have taken a different direction with this, but I have made several batches of garden stake shafts over the years, and this year bought a hundred of the Chinese bamboo shafts off Ebay. I will NEVER again bother making a shaft from garden stakes. TheC hinese shafts came 34" long, spined, not weighed, and I got a hundred of them for 129.00. The quality of the material is AMAZING, although there is styill a lot that goes in to straightening and building the shafts.
Now, regardless, One good trick for bareshaft tuning is to make several heads that can compression fit or screw on, of different weights. I use the PEX plugs for blunts, and you could chuck them in a drill and remove material until you had a set of 160, 145, 125, 110 grains, etc... that can be forces onto the end of the shaft. If it's too small, wrap it with tape or thread first, or whatever. You could do something similar with large nuts of different weights. You could even wrap them and insert differentm lengths of rods or 16 penny nails or whatever to play with head weight.
Some of the Chinese guys on Ebay sell field points that have parallel insides just for bamboo shafts. Search Chinese arrow, and look for field points. They slip on a bamboo or wood shaft,a nd are glued or crimped on. You can also do the thread wrap with glue and then slip that head over the wrap and glue it again.
Inconsistency of the diameter is a reality of life with the bamboo shafts, because while they are all the same diameter generally, they just vary from, say 5/16 to 11/32 and it's all about node spacing, and there is nothing you can do about it. Either your point end or your nock ends or both are gonna all be different diameters, just slightly. I Wrapped the head ends of my thinner ones this year with spiraling slips of tough paper, and either one or two layers soaked in superglue would do it. I stained the paper and a little sanding took care of the rest.
