I've been shooting benchrest over 20 years, and 1,000 yard benchrest for 15. I'm amazed at all the wives tales that still trap me, and you've just run into another one. What, that seating the bullets into the lands is a wives tale? No. The wives tale is that you can follow some formula and be comfortable that you are doing the right thing.
Different barrels like different things, and it matters not a whit what you like. I remember when Berger was advocating jamming all VLDs, certainly not jumping them more than .002. So, 'ol Charles Bailey, an IBS 1K shooter of the year, found his rifle shot best when the 210 Berger VLD was jumped .020 -- ten times the recommended maximum. He did this the old fashioned way, he tested. Today, of course, Berger also recommends trying a big jump with VLDs, much bigger than .020 . . .
Several things to consider. If you can, always try seating bullets "long," that is, into the lands. You might get your best groups there. You may also find it a fussy point, in that .010 into the lands (based on your establishment of "into," the actual number means nothing) shoots lights out, but .002 either way is ho-hum. At the same time, you might find a broader window at another setting, farther in, or even .020, .040, or .100 off.
Now you have to choose. Just how consistent are your components? Your reloading? You will likely also find that neck tension will affect the results, as will powder choice. Change one, the others may change. May not, too.
Too much! you say. When tuning a rifle (barrel), you start by ruling things out. Three shot groups are good enough, and for ruling things out, 100 yards is far enough. Reasonably quickly -- 30 to 50 rounds -- you are down to a powder to work with, a bullet that shows promise, and a seating depth range that shows promise. Keep working, you'll have it within another 30 rounds.
You'd think that since I "know" this, I'd do it right. Sure. I'm on my 4th barrel with a certain chambering. The first three all liked Rel-22, Rel-25 or VVN-560. One like magnum primers, the rest standard. So on goes barrel No. 4. None of this shoots well. Another "score" barrel I figure. But somewhere in the murky region of what I use for a brain, I remember that many-times National Champion Danny Brooks shoots a chambering quite close to mine, and favored 4831. I try it. Four inch groups at 1K (that's good). Clouseau, I tell myself, you've done it again.
I see a lot of "explanations" in this thread on why something is "best." Go look at Stan Ware & Al Nyhus's Wolf Pup chambering. The whole neck is only .125 long. Several rifles shoot lights out. How does that fit with all the pet beliefs?
Two things. One is the theory is wrong because we all went from what had worked to formulate explanations of why it worked, and concluded something was best -- true, if you want -- on too little data. Obviously there is more work to do, or the Wolf Pup wouldn't shoot so well. The second is to think you can test one thing at a time and arrive at the optimum setup. Not unless the theory is as predictively good as, say, Einstein's Relativity theory. And it ain't. We still have things interact in unpredictable ways, primers, powder choice, neck tension, etc.
Most important is to learn how to work up a load for a barrel, a testing technique. By all means try what's worked before first, but don't forget another 3 to 6 shots lets you try something else.
And don't pass on old wives tales if you can help it.
Good luck, and welcome to benchrest.
