I have been using Berkley Big Game 15lb. for king salmon from the bank on the Feather River in California. I broke a rod and broke the line at a blood knot. When the fish are snagged they are doubly difficult to bring in (and release). I'm told that Berkley Big Game at 15lb. is more like 20lb. Is Big Game at 15lb. sufficient? What about casting properties of stronger line?