No. The number is a reference to the spine not length. In my estimation, the Microflite shafts were the best fiberglass shafts ever made. Back in the early to mid-60's, they reigned. If I recall the story that went around when they stopped making them, Browning sold the patent to Bear who saw them as too much competition and Bear buried them. I have one of the old charts around somewhere but can't put my finger on it at the moment. I recall that the number 9 shaft was rated for 50 or 55 lbs at 28. I shot a Jack Howard Game Master, 66 inch and 60 lbs at 28 and used a number 11 shaft cut to 28.5 inches with a 130 grain Zwicey Delta broadhead. Much to my chagrin, I only have 10 of those arrows left. If I can locate the chart, I'll send you a copy.