Dan,
The sahfts are made from Gold Tip, as is the brass insert, but it is a heavier insert then the one they normally produce. We then have them fletched and nocked on our end.
I am not sure where the 2 different weights came from. There is only one arrow. Yes, weight does vary from shaft to shaft, but we have found them to be very close. The arrow that we use on the Premium Hunter arrows are the same as the regular 6 pack, but we weigh them and tune them with the broad head on. They are within 2 grains of each other on the Premium Hunters.
We use the superbrite inserts for 2 reasons. One, they are easy to seeboth during and after the shot. The second is they have a square notch in the back. This is so you can put a nock tool in to easily refletch your arrow in a standard fletching jig.
I hope this clears up any questions. If not, let me know.
Randy