@Reaver
sounds like a critical glitch where you burned some edge to downgrade it to a simple glitch 
what it really shows is just how dangerous gunpowder really is!
3.7 grains is LESS then a quarter gram of extra powder. Yet that quarter gram exceeded the tolerance of a hardened stainless steel .357 magnum revolver!
Explosives are dangerous things to mess with, and when you consider that all a gun is, is a EXPLOSIVE device that directs the explosion along a linear path.
(Hammer hits the primer cap, creating a spark, spark ignites the powder causing an explosion and rapid expansion of gases, the gas then pushes against all sides of the shell equally. The lead, which is just form pressed into the cartridge is the weakest link, causing the lead to expelled...)
In my case, that rapid expansion of gases pushed on the walls of the shell, and BLEW OUT the side of the cartridge, the force of which blew out the cylinder! (turned it into a basic U shape). If I remember correctly, the lead was still in the cylinder! (so It didn't even clear the barrel).
Now, all that said, I still hand load. simply because I like to shoot, and shooting gets expensive when you are not buying just .22 rim fire. In Canada, so no idea about the prices in the States or else where, and I have a large collection of fire arms that if I want to shoot, I am basically forced to hand load. Still costs me thousands of dollars a year, for the amount I shoot... but that still beats store bought for savings.
I haven't read the rules for hand loads in the new book (don't have it yet), but it is possible to tweak the powder to tolerance ratios to get a little more "bang" for your "buck", but.... as my case shows, those tolerances are closer the many people think!