[Jeff Higgins]

I prefer full cases, if not even compressed charges. Granted, that is easier to achieve in rifle loads, but it can be done is pistol and revolver loading as well. Magnum revolver loads are the easiest as far as finding powders to fill the case; 2400, W-W 296, H110 and the like will fill 'em up. Impossible to double charge with any of those.

Small capacity autos are next easiest. Unique, W-W 231, Universal Clays, and other powders in that burning range will generally fill even a .45 ACP case enough to preclude double charging.

It's the old, low pressure "standard" revolver rounds that are the toughest. Most perform at their best with light charges of relatively fast burning powders; charges that rarely even fill half of the available case capacity. Those make me very nervous. I've taken to using powders on the slow end of suitable for those, even going as slow as 2400 in standard velocity .38 Specials, .44 Specials and .45 Colts.

The .45 Colt is the worst of the lot, with a case meant to hold 40 grains of black powder. Typical loads with fast pistol powders are in the range of seven grains of 231 or nine grains of Unique. One could conceivably get far more than a double charge into one. My "standard" load of 16 grains of 2400 fills the case over 3/4 full, as the 2400 bulks up so much more than black powder. A double charge will spill over the top, immediately alerting me that something is wrong.

The other important safety step I employ is to store the powder away from my loading bench, only allowing one can at a time out on that bench. The powder measure is emptied and the can returned to storage before the next can comes out. It is often impossible to tell by appearance what is in the measure, especially with ball powders or extruded powders. The wrong powder can be even more dangerous than a double charge of the correct powder. Imagine loading 80 grains of W-W 296 into a .375 H&H case when you thought you were loading W-W 760... probably wouldn't survive that one...