I wouldn't use the brass .410 case for anything other than .410 shotshells...other have tried to fill the gap with a cartridge known as the .45 Mongo which is made by necking up a .444 Marlin to accept .45 bullets..be careful of that one..heard bad stories...a gentleman on this forum has developed a round using 9.3 x 74 Rimmed brass..he fireforms the brass after necking up to .45, but uses mild to moderate .45 long colt data with a filler of poly fillers to hold the powder down on the primer. You might want to search for it, but I forgot what he named the thing..