Matt,
You make a great point. We have been telling folks for years that the VLDs TYPICALLY shoot best when touching the rifling. This information came from the fact that back when the VLD was introduced many of those who shoot heavier bullets,maybe most) were jumping their bullets.
The larger bullet makers relay that you need to jump your bullet to avoid pressure problems. The truth is that the pressure increase by touching the rifling is small,it does increase pressure so if you are already using a hot load you should back down a bit before testing loads with the bullet in the rifling). However the increase in pressure by touch the rifling is not nearly enough to cause a safety concern,UNLESS YOUR LOAD ALREADY GENERATES HIGH PRESSURE-disclaimer published
The recommendation of jumping the bullet by these bullet makers is actually because of the fact that in many cases,maybe all) they are using multiple dies to make bullets that end up in the same box.,There is no other way to make quantity without using multiple dies as machine can only run so fast)
Since it is impossible to make ogive dies EXACTLY the same you end up with bullets that will give you a variation in the base of the cartridge to the end of the bearing surface,where the bullet touches the rifling). This can occur even if the dimension from the base to the ogive of a bullet is exactly the same since the distance from the base of the case to the end of the bearing surface is set by the seating die and the relationship between where the bullet touches the seating stem and the ogive shape,not the base to ogive measurement of the bullet).
This is very important because if the distance from the base of the cartridge to the end of the bearing surface varies significantly due to slight differences in ogive shape and you are near the rifling you will have some rounds where the bullets touch the rifling and some rounds that don't touch. This inconsistency is very bad for precision which is why these larger bullet makers tell you to jump your bullets because then you are always not touching the rifling which increases their precision potential,makes them shoot better).
I mention all this because when the VLD was introduced most shooters tried the bullet with a jump. Many were successful but others had trouble. When those who had trouble extended the COAL so that the VLD touched the rifling the precision improved. That is were the statement of "TYPICALLY the VLD shoot better if you touch the rifling" came from. So what we should be saying is that "IF you are having precision trouble with the VLD the best thing to try first is to put the bullet into the rifling at least .010."
Now that the VLD have become much more popular we are getting many reports that they shoot well when jumped. So the proper thing to do is to try the VLD at both .010 into the lands and .010 off of the lands and if it matters in your rifle,sometimes it doesn't) then this test will tell your pretty quickly which is better for you.
Regards,
Eric