A gas check can be a worthwhile addition to a cast bullet, because it protects and strengthens a bullet’s base against the pressure from burning powder, and a perfect base is probably the most important factor for a cast bullet to shoot accurately.
Handloads and the 9mm Luger are not a good fit according
to some shooters. They state only a narrow band of
function is possible with the Luger, and the handloader is wasting his time – but the opposite is true. Any
loading ever made by a factory can be duplicated or bettered by a careful handloader.