Most of us .....for the clay target games, shoot the .410 at the same ranges we shoot the 12ga, 20ga and 28ga.....there is really no difference.
1/2 oz of 8's out of a 12ga or a .410 ....at 1200 fps .....will go downrange exactly the same in terms of range, how hard each pellet hits and its ability to break targets...kill upland birds, etc...
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I've never talked to anyone else that says these adapters will work in a pump gun....you may have come upon something really new...