Ideally, anytime you change a component, especially one such as the new bullets you're describing that are obviously different dimensionally from the previous Lot, you want to do a completely new load workup. However, if you see how the new ones shoot relative to the old, you can re-measure the distance to touching with the longer bullets, start at the same previous optimized seating depth, then see how they work. In that scenario, you'll have approximately .027" more bullet shank seated in the neck, so it might be advisable to drop the charge weight a tenth or two, but if your previous load was well under MAX it probably won't make much difference.
In my hands, maintaining the appropriate distance between the bullet ogive and its initial contact point with the lands is the key to seating depth optimization. As I have mentioned previously, the BTO dimension is all below/outside of that region. As long as the bearing surface/boattail of a new Lot of bullets isn't so much longer than the previous Lot as to dramatically increase pressure by taking up a substantial amount of previously unoccupied case volume, seating the new bullet with the same distance relationship to the lands is a reasonable starting point if you don't wish to take the time to do a complete workup. Maintaining constant CBTO with bullets of varying length is not difficult.
I am not stating that the BTO region of the bullet has no importance in the reloading process. The most obvious factors that can be affected by variance in the BTO dimension are pressure (i.e. longer BTO takes up more case volume, thereby increasing pressure at a given charge weight), friction, and the amount of "grip" the neck has on the bullet. However, many rifle setups are often simply not sufficiently accurate/precise for these variables to play a major factor. For example, when a shooter does a traditional seating depth test that covers a common range, let's say from .003" off the lands to .033" off the lands (.030" total range), the amount of bullet shank seated in the neck generally changes proportionally to the seating depth. It is often possible to detect subtle changes in velocity/pressure at each increment as the the bullet is moved farther away from the lands. However, these changes can often be quite small, as in smaller than the ES/SD for a 5-shot group, or the effect on average velocity of changing the charge weight by 0.1 gr. They are certainly present, but of a magnitude that is typically outweighed markedly by other factors affecting precision; i.e. major sources of error or variance. Those larger sources of error are the ones you want to address first.
One other thing you might want to consider is dimensional variance in other regions of this new Lot of bullets. You didn't mention the bullet OAL. Is the average bullet OAL about the same as the old Lot of bullets, meaning the nose region of the new bullets are shorter than the previous Lot? Or is is longer, meaning the nose region of the new Lot of bullets is equal to, or even longer than the old Lot? As you can imagine, changing the length of the nose region means changing the bullet ogive radius, something that can very easily affect the desired optimal seating depth. It may or may not be the same as the previous Lot, depending on how how different the two Lots are. In any event, no type of sorting will ever tell you with complete confidence exactly where a given load wants to tune in. Only rigorous load development and testing can do that. That is why most reloaders will tell you that when you change a component such as the Lot of bullets, it is usually a good idea to re-develop the load. In your specific situation, I doubt the longer BTO will be enough to markedly change the optimal charge weight. If it does, it's likely to be by no more than a tenth grain or two at most as I mentioned above. However, optimal seating depth might end up exactly the same, or very different. There is no way to know with certainty in advance, so you might just want to set up a new full seating depth test at the old charge weight. You can measure velocity at the same time and determine whether the charge weight needs to be tweaked a tenth or two to re-produce the same velocity as the previous Lot of bullets. In fact, there are a variety of ways you could go to try and minimize the amount of effort and components that you put into getting the load with the new Lot of bullets to shoot like the old ones. However, anything other than re-working the load completely will be to some extent "cutting corners". Sometimes that works, sometimes it does not.
