That sounds very much like the Nosler Solid Base, the bullet that eventually got a plastic point and became the Ballistic Tip. But when the Solid Base bullets were soft-points, they held together very well, even at pretty high velocity.
A few years back and friend and I each had cow tags for the Madison valley. We had access to a big ranch we were living on and could choose our moment to execute our cows. The day finally arrived when elk cooperated so it would be a simple thing to get the truck to the fallen quarry.
My friend was shooting a 300 WM with handloaded 180 NAB's. I had a 270 WIN with handloaded 150 NBT's. We each picked out our cows, both similar sized (on the large side), and both shot. Each of us hit our cows about identically through the ribs/lungs. The range was essentially identical, right at 150 yards. Mine tipped over almost immediately after a couple steps, his took a 25 yard dash. His Accubond was under the hide on the offside, my Ballistic Tip passed through.
So none of this has any bearing on anything, being an example of one, other than that day the 270 was at least the equal of a 300 WM on eating-sized cow elk, and that Ballistic Tips are more bullet than many think!
“Perfection is Achieved Not When There Is Nothing More to Add, But When There Is Nothing Left to Take Away” Antoine de Saint-Exupery
