My current set up is a katera XL, drawing about 71 lbs, and my DL is 31." My arrow length is 30." I plan on switching away from mechanicals this year and shooting ST magnums. I am going to try easton axis n-fused arrows. My question is 300s or 340s? There is a pretty significant difference in gpi and would prefer the 340s so save some weight if possible. Is this enough spine? The easton arrow selector chart says 340 but I never believe those things. Thanks guys.