Very unfortunately........ the club doesn't spend much time updating their 600yd range. And, unfortunately the State Police and Sheriff's departments use it and shoot everything all to heck (polite word). They use very large rubber belts to staple to and they're litterly filled with staples. I'm lucky to get a target stapled on them.

However... you're right. I don't use cardboard and its also the type target I'm using causing the problems. Ain't no bullet tumbling grouping like that at that range....