Developed by Ed Whildin and introduced in 1988, the 50 Action Express (AE) was originally designed with a true 50-caliber bore (50/100-inch bore diameter; 51/100-inch groove diameter). However, the polygonal rifling used by H&K creates relatively shallow grooves, so the special rod used by the ATF to delineate between what it deems a sporting arm verses a destructive weapon fell right through the barrel; classifying it as a destructive weapon and therefore it was subject to all manner of restrictions and requiring a Class-C license to sell or own. The round was redesigned, by tapering the case, so it would use a 0.500-inch diameter bullet. As such, the new bore-size passed the test and the gun was classified as a sporting arm. The 50 AE typically launches a 300- to 325-grain bullet at about 1500 fps. Therefore, it is far more powerful than the 44 Magnum but far behind the 454 in terms of energy. Owing to the heavy gun and semi-automatic mechanism, recoil, while significant, is not punishing for most shooters with big enough hands to handle the gun and hold it properly. I am not among that group. My fingers are too short to allow me to comfortably hold it, so shooting the Desert Eagle is generally not pleasant for me. Those with bigger hands and particularly with longer fingers do enjoy shooting one. With the best components and good handloads, the 50 AE in the Desert Eagle is a formidable fight stopper and suitable for big-game hunting of most non-dangerous species, worldwide. As with any pistol round headspacing on the case mouth, best practice is to apply a taper-crimp after seating the bullet. This helps to lock the bullet in place against chambering forces that might otherwise drive it into the case. I cannot too-strongly recommend getting a second seating-and-crimping die so you can have one adjusted to seat the bullet and the second adjusted to only taper-crimp the case mouth. Generally, attempting to do both operations in one step is a recipe for damaged and destroyed cases.