What kind of component substitutions do you guys do on manual loads (different bullet, different primer, etc)? Here is my opinion though I don't sub much at all: Powder - Never, ever, ever EVER. Wouldn't even think about it. Primer - Have subbed magnum for standard small pistol on a "safe load" (was a mistake) for .357. I also accidently wound up with a crapload of Small Pistol Magnum primers. The load was below the book charge though (110 gr Speer bullet on top of 17 grains of 2400). Probably wouldn't do this if I were pushing the limit. I have also subbed Winchester for CCI standard primers. Bullet - this is my real question. I haven't done it but can you sub a .357 Magnum 140 grain Sierra or Nosler bullet for a similar-design 140 Grain Speer? What makes me think of this is I have seen a few bullet manufacturers that don't have manuals out.