Ed Schlief of ABS says this happens not due to inferior quality, but because plastic nocks are the weakest part of the arrow and esp. so given the extreme narrow taper at the backs of the shafts, limiting nock size. Maybe they will find stronger nocks but for now most shooters just don't glue them in, making 'em really easy to change if they snap off ... like I had one do earlier today when tuning a shaft with the 300-grain ABS field point, like a darned torpedo, and shot plumb through two backstops and 3" into a tree. The nock broke but the front end of the shaft and the adaptor hardware were unharmed,w hich is where it counts. I'm a woody shooter but experimenting with the GrizzlySticks because I want to try the new Ashby-style "armor-piercing" broadhead. I'm tremendously impressed, so far, that this massive setup, at 764 total and most of that right up front, seems to fly as fast and flat as woodies a hundred grains and more lighter. I'm also noticing better flight and groups with woodies using Woody Weights and heavy points. Like O.L. Adcock says in the neighboring "Perfect arrow" thread, having extremely high FoC arrow balance gives the feathers more traction to keep things straight. Which is way off the nocks topic, sorry. dave