actually they can be used as jackets for .224 Dia bullets.....Yes, there' s a company that makes tools to swage bullets using .22 rimfire empties....they can also make .243 bullet jackets as well. It' s how Joyce Hornady started making bullets and you can still do it today.....check " Corbin" for reloading tools and extruded lead wire.....there' s a lot of good in those spent .22 long rifle cases!!