.429 DE

The .429 DE (10.9x33mmRB) is a cartridge introduced in 2018 by Magnum Research for the Desert Eagle line of handguns.

Design
The .429 DE is a .50 AE case that is necked down to accept .429-diameter (10.9mm) bullets used in the .44 Magnum. The cartridge features a 25% increase in velocity and 45% increase of energy over a standard 240-grain .44 Magnum load of 1285 ftlbf at 100 yd. The .429 DE offers increased speed and accuracy over the .50 AE due to its lighter and slimmer projectile. Also, due to its use of the same cartridge design, one can easily convert a .50 AE Desert Eagle to .429 DE with only a barrel change. Though very similar to the obsolete .440 Cor-Bon, it is not interchangeable with that cartridge. The same bolt and magazines can be used with both the .429 DE and the .50 AE-chambered Desert Eagle. In 2021, the .429 DE was accepted into SAAMI standardization.