Murat, close but no cigar! You almost had the Italian translation deciphered but it got the best of you
What he does with his guns is basically design each gun size differently around its center of gravity and ballast placement consideration in the mould design. Since for each gun size there is a specific mould, and you can't exactly change a carbon fiber mold cheaply or easily once it's been made, the longer guns like the 130's tend to have a different shape than say the 75cm and 90's, with the objective of making the gun as easily to handle and maneuver through the water taking into account its size. This is one reason they are such a well like engineered spearguns in Italy, he calls it a natural extension of your arm in the water without any firm linear (strait) limitations such as a traditional round barrel speargun, like the shape of our arm for example isn't round.
A very optimistic undertaking in as far as carbon fiber spearguns are concerned, and based mostly around the use of the power of one band to achieve the optimal balance between bands and power.
I talked to Mr. Bonfanti once, the owner and mastermind of C4, and when we spoke about what the logistics of trying to do the same thing for a properly balanced blue water gun, the amount of carbon fiber needed to make it, and mostly the cost consideration kind of shut the idea of the project down fast.
This is why teak, as high end and seeming expensive wood as it is, is a ten times easier and more cost effective alternative to build a properly balanced multi band gun with the above mentioned considerations. The cost is much, did I mention VERY MUCH, more affordable and realizable and less than half the trouble. Milling it and shaping the wooden barrel is ten times easier and cheaper. You didn't didn't hear Bonfanti say this though, I did

To him carbon fiber is obviously the best material for anything in the world regardless of cost
