La cartouche en question:
D'après ce qui en est dis sur Worldguns.ru elle est intermédiare entre la 12.7 et la 7.62 OTAN.
The incredible long distance accuracy of the Intervention is due to the revolutionary new .408 Cheyenne Tactical cartridge.
The cartridge was developed from the ground up to deliver sub-minute accuracy at 2500 yards and beyond. The projectile is based on the patent pending “balanced flight” design developed by Lost River Ballistic Technology.
This balanced flight design eliminates the precession and overspin that cause inaccuracy in conventional projectiles.
The .408 is available in both 419 gr. (3000 fps.) and 305 gr. (3500 fps) versions that were designed for mission specific performance.