Joe,
Sounds like you're doing pretty much everything right. As others have pointed out, don't get too crazy about the overall case length - it's going to vary some, and the variances you reported aren't bad at all. As far as avoiding pressure spikes, the two obvious biggies are 1) too much powder (duh!) and 2) OAL so long that the bullet is engaged with the rifling. The plunk test should check for this, but I'd buy a case gauge. They're not that expensive, and give a lot of peace of mind.
I remember when I first started loading the .45 ACP in 1976, and I sweated bullets over cleaning out primer pockets, trimming case lengths, weighing every charge twice, and randomly weighing bullets, just to be sure. Now I tumble the cases to make them pretty, use whatever large pistol primers I have on hand, and weigh the 1st 5 charges to make sure everything is working right, check the finished product against a case gauge, and crank 'em out on the Dillon (highly recommended by the way). I almost always set my powder loads at halfway between the recommended minimum and maximum. Unless you're in competition target shooting, you'll never notice any variations in accuracy.
I like WW 231 a lot, as it's economical and can be used in a variety of pistol cartridges. My only concern with it is that it uses so little that you might not notice an accidental double charge. Unique takes a larger volume, and might prevent that. Just stay focused while you're reloading and you'll do fine. I prefer copper plated bullets, as they don't lead up the barrel as bad as lead, and are a LITTLE cheaper than FMJ. I shoot mostly 200g SWC bullets. Right now I've got a bunch of 200g SWC Lead bullets over 5.6 WW231 at 1.250 OAL, and they work just fine through my Commander and Gov't model. Just FYI, I tried 200 g SWC copper plate bullets from Ranier, and they turned my pistols into jam-o-matics. I have absolutely no idea why, as they looked identical to the lead bullets in that weight/design I had been using. Maybe a fluke.
And, yes, I remember the time I shot my first reload. I was behind a tree and stuck my arm around it to keep the tree between me and my face.
