Nick LC wrote:
I went on the river with a 6wt floating line and it cast like a charm....after casting the 6wt on it i feel it could even be better with a 7wt, the rod have a lot of power !
Nick, Welcome to the Forum!
Your quote above perfectly describes how to determine the correct line(s). You took the rod to the river for test casting. Yes, it really is that simple. If the rod hadn't cast like a charm, you had the wrong line! If the rod feels stiff, the line is too light. If the rod feels lethargic and soggy, the line is too heavy. Any line that casts well is a correct match for your casting style under those conditions. Don't make it any more complicated than necessary.
Casting a plastic bag of pocket change isn't a fishing technique I've ever used. It isn't a good way to test fly rods either.
Tom