The newer shells have shot cups and buffering to protect the shot form the choke. My 20 gauge double is choked Improved and Modified. 20 pellet #3 buck patterns 5" I and 4" M at 7 yards while my cylinder 12 gauge patterns 6" with 9 pellet 00 buck at 7 yards. With cylinder you can expect approximately 1" per yard.
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"I would not be an old man if I had not been an armed young man." JTJ
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