Here's an old post from the Box O'Truth talking about making and shooting "dum dum" bullets.
Their conclusion is that it's a lot of work to do, and probably doesn't appreciably increase expansion in lower velocity rounds https://www.theboxotruth.com/the-box-o-truth-32-dum-dum-bullets-and-the-box-otruth/
Their conclusion is that it's a lot of work to do, and probably doesn't appreciably increase expansion in lower velocity rounds https://www.theboxotruth.com/the-box-o-truth-32-dum-dum-bullets-and-the-box-otruth/