I used to be a machinist years ago and some of the parts that we inspected we did a concentricity test on a metal shaft just 4" long.If the shaft was even .003"of an inch it was rejected.Now just think;three thousands of an inch of a four inch span compared to an arrow shaft that is at least 25"thats an awfull large error.Spin test any arrow with a broadhead at the end ,on a streight arrow with an "even" glue line, and you can even see some wobble wich could be from other factors other than the shaft .I would get the straightest arrows possible or that I could afford,You do get what you pay for most of the time.Hey and in archery or any target sport isn't accuracy paramount?Hunting too!