That is some serious velocity. Interesting that the slow motion film showed that the projectile seems to have a flat nose profile.
The following is just some personal information, from when I use to do Hand-Reloading. I did some pistols (38 cal. & 45 cal.) As well as my all time favorite, 35 Whelen (poor man's 300 Magnum Holland & Holland, for the first 100 yards) a.k.a. Wildcat[er]. (Meaning, at the time when I was doing reloading, it was the only way to have ammunition to shoot the rifle.) It was also, quite impressive when shooting at the range, it was ALWAYS with out ANY DOUBT, THE LOUDEST, (everyone would come over and ask, What the hell are you shooting, a Cannon) and the biggest (middle of a very sunny day) easy to see; no squinting necessary, FLAME THROWING (S.O.B.) Rifle.
A lot of different Caliber(s) Pistol(s) / Rifle(s) have ammunition, with flat / blunt nose's. Depending, upon the manufacturer, would determine just how much of the nose is flat, compared to the rest of the "bullet," that was loaded into the shell casing.
On my 35 Whelen, caliber diameter was 0.385" in. Dia. On the 180 GR. Flat Nose & 220 Grain Flat Nose, approx Dia. of the "Flat Nose area", was close to something like 0.1875" in. / 3/16th's.
For what it's worth, the rifle(s) I reloaded were: "25/06," the "30/06," and my trustee ".35 Whelen." They ALL USE THE SAME Brass shell casing. Just a matter, of necking {resizing} "Up" or "Down," from the "30/06." Made shooting, VERY CHEAP, affordable.
Wadcutter