When Pole archery started the arrows where made of "wood"...these where used for many years. The bows used where long bows with steel cable. Then recurved bows came into use and the same arrows where used.
As years went past they invented a compound bow and went with a stronger arrow..."carbon 2540"...as the wooden arrows turned into toothpicks when the fork/bar was hit.
Carbon arrows worked well for some time. Then bows got stronger and the arrows where breaking on impact with the fork/bar...similar to the wooden arrows. It wasn't uncommon to break 3 arrows on a evenings shoot.
This made "Ray" at Heartland Archery smile with delight as most archerers had their arrows made there.
Around 1997-98 Chad Swayze asked Heartland to make him an arrow that would be stronger.
The first arrow developed was a carbon inside a carbon...this worked well and didn't break. It was much like shooting a log. We still have the arrow after many years of shooting.
Then Ray developed an arrow that we have been using for the past seven-eight years.
All shooters now use a carbon arrow inserted into a aluminum arrow witch gives us strength and a light wait arrow.

Heartland Archery site. http://www.ca.nationalarcherysupply.com