They'll blow up alright! That's why I only used them one year when they blew up on the ribs of a cow elk and buck deer out in Wyoming and made a mess of things. Then I went to handloading their SP and BTSP Interlocks and ever since then every goat and deer I've shot has had perfect expanion and penetration with minimal loss of meat and the animals haven't gone ten yards total. I've heard good and bad about the SST and I think it all depends on the caliber and speed that it's going as to whether you get good or poor results with them.