"What I would like to get is a book/books that explain the different aspects of "Precision" reloading, above what the reloading manuals say."
You want the "Precision Shooting Reloading Guide", Dave Brennan. I have several other "advanced books" that cost much more and give MUCH less help. It has eight chapters, each one is authored by recognised talents so it isn't myoptic in approach. Chapters cover an over-view of reloading for accuracy, competion with bolt AND gas guns, BR, magnum sporting rifle, wildcats, cast bullets and general accuracy load develpment. It's loaded with info, there is very little light chatter or fluff.
( Published by: Precision Shooting, Inc, 222 McKee St., Manchester, CT, 06040. I got mine from Sinclair International but I've seen it in better reloading shops and on Amazon.com.)
Before anyone else gets to it I'd suggest you skip the often recommended "Handloading for Competition", Glen Zediker, unless you actually shoot competition and do it with gas guns. Glen is certainly knowledgable but he's a college professon who loves the sound of his own voice so there is a LOT of chaff for most shooters to sift out to get a few kernels of real info. But, he tells us right up front he's speaking to competitors! (Okay, Fitch beat me in here!)
I would also caution against another Precision Shooting, Dave Brennan, book "The Benchrest Shooting Primer" unless you are actually headed into heavy duty BR competion. It's massive and has a LOT of info contributed by MANY experts but it's rambling and most of it ONLY applies to serious BR shooting. In fairness, the title says it's for BR, not hunters or varminters.