This year, I purchased a rare 28" .410 NID ejector gun. It was marked M/F, but when I got it home it measured .010/.000". I was disappointed. But, that kicked the door open for me to "butcher" it and lengthen the chambers from the 2 1/2" to 3" with some long cones. I've been hunting it on everything from pen raised pheasant and chukar to wild quail. That cylinder bore is good out to quite a bit further than anyone, myself included, would expect for killing birds with a 3" shell. The pattern board show excellent patterns.