I am a lefty and snag has got it correct.
Adam, others are correct about how the arrows can look in the target, it can fool you. What you need to watch is the arrow as it flies toward the target. If it is tailing nock right, then it indeed is weak. As yo cut them down a little at a time you will get better and better flight. Leave them ever so slightly weak as snag said, by the time you add 30-40 grains of feathers and glue they will be spot on.
Don't forget to record your brace height and nock height and make sure you shoot your bow vertical during bareshafting too. Then, to confirm tune during season, shoot a bareshaft with your other arrows during target practice. It will confirm your bow tune, and more importantly.... confirm YOUR tune, haha ! Feathers will make up for a world of bad form issues, but a bareshaft will tell on you everytime !!! JMHO
nocams