The amazing thing is how long it took to reinvent this capability, and then, not so well as originally done. My Evans is a 2.5 inch four-shot grouper at 100 yards and still throws modified patterns of no. 6 shot. A RBL "Professional" (20ga sxs rifled slug gun)will be lucky to shoot a four-shot group that tightly and won't shoot shot in any sort of usable pattern.