Help ! I'm busting strings all over the place here. I bought an acoustic baritone which is tuned B E A D Fsharp and B. I want to tune to half nashville tuning so need to raise A and D strings by an octave. The baritone strings were 70 60 48 29 22 and 16. I had some Martin SP custom lights lying around and substituted the A string for a 32 and the D for a 23 and bust the both. Any suggestions? Should I be using the light strings from a 12 string set? Any advice much appreciated. Thanks.