When I was shooting registered skeet, I loaded several thousand .410 shells a year. Early on,I found that I couldn't get a true 1/2 oz of magnum shot in a Win AA compression formed hull, so I went to the Remington ribbed hulls for reloading. I used WW 296 powder, Remington or Federal wads and Win 209 primers. I actually reamed out my shot bar to throw the maximum legal load for skeet and that is a bit over 1/2 oz when using magnum shot. Use of magnum shot pays off in the .410 with better patterns and more broken targets, much more so than with the 12 or 20. Be careful though about primers - Those little shells are already operating at max pressure, so a hotter primer will cause "bullets" with the whole front of the shell going out the barrel. The use of Remington or Federal wads was important because the wads for Winchester compression formed hulls wouldn't seal adequately. Those reloads worked well enough to get me into an AA class back in the day.
