That much…? Do you vary it one way or the other for any particular reason?
It depends on the meplat diameter, the jacket thickness, the distance you want expansion, the game you're shooting, etc.
I don't mean to make it sound like its so precise that its ridiculous, but here is my point.
The Berger EH is so explosive up close that you have to stay away from shoulders of large game (IMO) but it expands very well at fairly low velocities (distance).I see no reason to mess with the tip of the EH because they are always open (unless you ding them badly) A Berger hybrid target has a thicker jacket and might work much better than the EH up close on an elks shoulder, but loses expansion quicker than the EH at distance. People may argue and say, "Ive had good luck at long range with hybrids". Maybe so, but generally speaking with all else equal, the EH will expand easier. the bore size and sectional density matters too. More bullet mass will overcome will overcome body mass better with otherwise equal bullets.
As long as you don't widen the meplat diameter in opening up the tip, there is NO loss in BC and the minimal amount of weight removed is insignificant.
Also, a Berger style bullet doesn't expand so much like a normal mushroom. The hydraulic effect of force inside the hollow of the tip, usually BLOWS the tip off flush with where to lead core begins, and THEN they either mushroom, or come apart, depending on the resistance encountered, and has a lot to do with impact velocity. If you've done much bullet testing, you'll see what I mean by how a Berger normally expands. Ive found countless tips that were bulged and blown off; some even inside animals.
This is why not only jacket thickness matters, but the amount of open tip to cause more hydraulic action, and why at times, at that borderline velocity that allows the tip to blow, results can be radically different! its also where most arguments start as to how good a bullet is!
If a tip doesn't blow, it can act like a solid but if it does blow, it can cause extensive damage. The difference could be only a few feet per second, or how open the tip is.
At the very least, you need to make sure the tip is open!