Lands

What do you load and how many thousands off the lans do you seat the bullet?

.308Win for an M1A. I seat between 10 and 20 thousandths off the lands to a max of 2.83" (max length of magazine). AMax bullets (and I suspect other VLD bullets) are usually limited by the max length of the magazine.

Ty

Depends on the bullet & the rifle.

I've a .22-250 that I can't find the lands on any more - it's been "shot out" that much, but still all but a one-holer gun.

Cast bullets in some .30 cal rifles I shoot get a hard-engraved OAL - seems to make all the difference.

Fer starters, I usually set the ogive at about -.010" & go from there.

& like 30Cal, it makes sense to allow functioning in your magazines. Sometimes that is the definative criteria & not a thing you can do about that.

The distance off the rifling depends on your rifle. Every one of 'em is different. Even two that were made one after the other will be slightly different. Especially, if the tooling was changed between them. Then add in the shape of the bullet and the age of the rifle. You really have to adjust bullet depth by trial and error.
Make up a few DP rounds(no primer or powder) and load the bullet out more until it hits the rifling then run the bullet seater in 1/8th of a turn. Find the best load for your rifle using the OAL given in your manual first. Adjusting the bullet depth is one of the next steps.

Find the best load for your rifle using the OAL given in your manual first. Adjusting the bullet depth is one of the next stepsSunray is correct, but keep this in mind: The deeper you seat a bullet, the higher the pressure will be.

Usually there are two seating depths for any rifle. One "long seated" where the bullet is out close to (sometimes touching) the rifling; and a second loaded to "magazine length". On my 700 Remington in .308 Win; the difference is close to half an inch.

I would be very foolish to work up a (close to) maximum load with the long seated profile and then just seat the bullets deep to magazine length. The result would be an over pressure round. It probably wouldn't blow up the gun on the first shot, but case life would be lessened, and the rifle would take more of a beating on every shot.

So, follow as Sunray suggested, but keep in mind the seating changes should be minor adjustments, not radical.

For what it's worth, most of my rifles shoot better with the bullets very close or on the leade.