Not quite a "Lazarus" or "Necro" thread, but always worth a look:
http://precisionrifleblog.com/2013/10/18/secrets-of-the-houston-warehouse-lessons-in-extreme-rifle-accuracy/
The most interesting part to me was the "Myth Busting", particularly regarding powder:
Myths Busted:
- Powder charges, as long as they were fairly consistent and bracketed within a couple of grains, were not important. He threw all of his charges with a Belding & Mull powder measure, and for one experiment he shot groups using three different powder measure settings (51, 52 & 53) … all three groups were identical.
- Lot variation in powder didn’t seem to have any effect on accuracy, even on when using IMR 4198, which has a reputation for varying considerably from lot to lot. He would just buy powder as he needed instead of laying in a big supply, because he found no evidence to support that powder lot variance affected accuracy in the least.
- He never saw an inaccurate primer, and was unable to detect any accuracy variances resulting from seating pressure.
- Rumors have persisted for years that some rifles shoot proportionally better at 200 yards than 100 yards, or vice versa. Virgil files that one under “occultism.” His experience in the warehouse was, if a rifle was shooting a consistent .100″ at 100 yards, it shot a consistent .200″ at 200 yards.
- He did NOT uniform primer pockets or turn the case bases. He also did NOT size his case necks.
The main heresy is that the
powder charge (amount and Lot #) was among the least critical factors.
Those who believe that everything is important, to where they even sort primers by weight can find ways to dismiss these findings, and so they should, but we need more than "All the winners do this list of steps, therefore they are all critical". The value here was that the conditions were controlled, and shooting skill was practically eliminated as a factor.