Info from the Hornady website from the link above in the thread:

450/400 Nitro Express 3"

Legendary performance from a cartridge that could only be made today.

First developed in 1902 as an all-around African cartridge, the original 450/400 Nitro Express 3" ammunition propelled a 400 gr. bullet to a muzzle velocity of just over 2100 fps. Over 100 years later, our engineers have replicated this African legend using modern technology and manufacturing process to perfect it.

Loaded with either a 400 gr. RN expanding bullet or FMJ-RN Solid, the NEW Hornady 450/400 NE 3" cartridges are perfect for modern single-shot rifles and the ideal ammo for hippo, buffalo and other thick-skinned game. Great pains were taken to ensure that this ammunition will regulate in double rifles.

Hornady's NEW 450/400 NE 3" takes an exceptional cartridge to new levels of perfection.

All components produced in-house to the most exacting specifications.
Newly-designed bullets are manufactured to 0.410" diameter and will perform safely in all rifles chambered for the 450/400 NE 3".
Cutting edge propellan technology delivers consistent performance from frigid arctic environments to the steamy heat of equatorial jungles.
Premium brass produced to the same tolerances as our Match brass.
Replicates original ballistics and is designed to regulate in doubles.

450/400 Nitro Express 3"

Bullet / muzzle / 100 yds / 200 yds / 300 yds

Velocity (fps)/Energy (ft/lb)
400 gr. RN 2050/3732 1815/2924 1595/2259

Trajectory Tables
400 gr. RN 1402/1746 -1.5 0.0 -10.0 -33.4

Velocity (fps)/Energy (ft/lb)
400 gr. FMJ-RN 2050/3732 1815/2924 1595/2259

Trajectory Tables
400 gr. FMJ-RN 1402/1746 -1.5 0.0 -10.0 -33.4

450/400 Nitro Express 3"