akinskwi, I draw your attention to this link for details:
https://www.ammunitiontogo.com/lodge/what-is-ballistic-coefficient/
But the short story is BC is associated with weight, shape, and sectional density (which is related to shape). There is nothing said about the tip per.se., but of course, the tip also relates to shape. So a pointed (Spitzer) bullet has a higher BC than a round nose.
I have to note that in your conversation above you referred to "base to ogive" 3 times, which supports my contention in post 24.
You said "But I did do a test where I sorted 100 bullets by Overall length “Base to Tips”,
Then by base to ogive. And sorted by the latter gave me the best results."
Did you do the test with final cartridges or just the bullets being measured? I have about 300 bullets that I purchased around 1985: 130gr Remington PSP (Power Soft Point) in .270 that I could never get any sort of acceptable group. Why this struck me to do, I don't know, but I measured 100 of them from the base of the bullet to the ogive and found that measurement ranged from 0.531 to 0.588, a difference of 0.057". And in those 100, the numbers were everything in between. Obviously, if I seated them all to the same COAL, case base to ogive, they would differ which I think explains why I haven't been able to get a good group. I believe the purchase was a sale, but the product was a bunch of seconds that qualified for the sale. When I measured 5 rounds from bullets made by Nosler, Hornady, Speer, Berger, and Sierra, I found very few differences in each series. Only Hornady had a larger difference than the others, but the bullet is sold for hunting and any difference in accuracy attributable to this is probably minor.