It is often recommended that you adjust OAL so that you have you bullet tip almost in the lands of the barrel.
How can you seat your bullets just short of the lands without any special tools to determine that you are doing it right?
Some rifles, just don't care if the "ogive" is close to or touching the lands. It's an old bench rest shooter's trick to seat the bullets tight into the lands. This makes up for "slop" in the chamber and the neck supports the bullet until it is well into the rifling.
If you have a very tight chamber or at least a tight throat, and everything is nice and straight, you shouldn't have to seat your bullet against the lands. IT WILL INCREASE SPIKE PRESSURES.
It can definitely make a difference in accuracy under some conditions. If you have a commercial, off the shelf sporter, it likely won't help enough to make a big difference.
If you're going to hunt with the rifle, it is only common sense to load the ogive at least .010 in off the lands.
Weatherby used to use a lot of freebore in their chambers to get away with the overbore capacity loads that were required by the proprietary cartridges chambered in their rifles.
Just one more caveat, PO Ackley felt that a bullet should be seated at least one bullet diameter into the neck and that the neck should be at least one bullet diameter long.