Don't load it, but have one loaded round around here some place. Looks like a .30 Carbine on steroids.
Quality Cartridge lists brass at $26.97 per 20. Loaded ammo at $49.97 per 20. Midway lists Redding dies at $74.99, currently out of stock, but a back order is ok. Haven't a clue if .406" bullets can be had.
The data comes from my 45th Edition Lyman book. Three bullet weights. Two cast, one jacketed.

Bullet diameter jacketed and cast: .406" or .407"
Max case length: 1.5"
Trim-to: 1.495"
Max OAL: 2.005"

200 grain jacketed
Powder Start Vel Max Vel
Unique 13.0 1597 15.2 1811
2400 22.0 1718 24.7 1915

212 grain Cast
Powder Start Vel Max Vel
Unique 12.0 1618 14.9 1845
2400 21.0 1773 23.5 1960
IMR4227 26.0 1915 29.0* 2074

240 grain Cast
Powder Start Vel Max Vel
Unique 11.0 1470 13.7 1672
2400 20.0 1669 22.0 1818
IMR4227 24.0 1506 27.5* 1968

Accuracy load: IMR4227 27.5* 1968 fps

"*" indicates a compressed load.