C:B ratio on my Cannon! :(

Ok first of all, this is the C:B ration on my FIRST cannon. I didn't have rat calc before this. And even worse I used the instructions in the BACKYARD BALLISTICS book, which abveously didn't have the correct meusurments. Ok theae are my cannon mesurments.
Chamber- 4" sch40 diameter, 15 inches long
Barrel- 2" diameter, 36 inches long
So my C:B ratio is____________ 1.61:1
to make me C:B ratio 1.00:1 my barrel needs to be 57.75" rounded to 58"
I have threads on my chamber so I can switch out barrels. If I were to go out and make a barrel long enough to make my C:B ratio 1.00:1 WOULD IT BE WORTH IT? Will it make a big difference?

Chamber- 4" sch40 diameter, 15 inches long
Barrel- 2" diameter, 36 inches long
So my C:B ratio is____________ 1.61:1

to make me C:B ratio 1.00:1 my barrel needs to be 57.75" rounded to 58"
I have threads on my chamber so I can switch out barrels. If I were to go out and make a barrel long enough to make my C:B ratio 1.00:1 WOULD IT BE WORTH IT? Will it make a big difference?

