I have done the opposite of this with an old Beeman pellet sizer, using the largest sizer that they made for it - I think it is 5.57 in .22 cal. It makes all the skirts the same size, but the heads just pass through untouched. It takes the skirts down slightly, but still below the diameter they end up in the barrel.would love to find a pellet skirt sizer , as in it flairs the back edge of the skirt out a few thousands forming a thinner lip edge . too fragel to ship as a maker but great to forme and shoot . then again maybe it would not work as envisioned ?