Metering is NOT the end-all and be-all of a good powder.
Unique didn't become the most popular pistol powder and stay there for decades because it meters well. It got there because, despite metering and burning "indifferently," it is amazingly accurate in a wide range of cartridges.
Even with its different metering, which is usually about +/- 0.2 gn and might occasionally be +0.2/-0.3gn, it still is very accurate. There is no single powder, other than Unique, that covers so many different cartridges so well.
For me, the worth of a powder is the target. It is only recently that handloaders have begun to expect 0.1gn metering, and some of us old farts shake our heads over what is being missed.
Take your powder measure and set it for the charge weight and simply load 10-30 rounds with Unique (particularly at 5.0 and 6.0gn--which seem to be "magic" load in .45ACP, 9x19, and .40S&W), fire at least two 5-shot groups (should fire five groups) at 25 or 50 yards, and see how it performs. You may just be surprised. Then do the same for other powders. A really good powder will perform well over a broad range of charge weight and do so consistently.
If you want one powder to test, go with 231/HP38. It meters well, it is accurate, and it isn't "temperamental" like some of the powders du jour.
Most versatile powders? True Blue is amazingly versatile from low pressure to high and may perform well in your guns. Sorry, but what works for me may not work for you, but I have been impressed with True Blue in .38 Special to 10mm Auto.
Silhouette is my favorite powder for almost any handgun cartridge in the 9x19/.40S&W class and will work in all of yours.
AA5, however, has tended to be a bit more accurate in my guns in light to mid-range loadings.
For 10mm Auto, where you don't want to download to .40S&W levels (otherwise, just shoot your .40), you need to look to AA9, Longshot, and N105.
I have a prejudice in favor of AA2, AA5, AA7, and AA9 for almost all pistol loads, with 231/HP38 being somewhat better than AA2 or AA5 in my .45ACPs and 2400 being better in my .45WinMags.
Last edited by noylj; 05-08-2012 at 02:32..