Hooboy! Wish this was asked earlier online...
My early (4-digit serial number) .357 Magnum Desert Eagle doesn't like ANY of the commercial loads I've tried to date. The only ones I haven't tried are Cor-Bon, if they make a 158 grain load to their usual level of performance that may cycle the beast. Sellier & Bellot might be another one. There is a website devoted to the Desert Eagle, and it has a specific page listing ammo that supposedly works for the guns:
http://zvis.com/dep/dep.shtml is the main Desert Eagle fan club page.
When talking to several powder manufacturers, I got a real education on the gun.
Accurate Arms sent me a nice email, stating that the Desert Eagle in .357 Magnum was almost too big a gun for the gas pressure of the cartridge, since the guns need a healthy bit of oomph to cycle their gas systems and slides. No problem with the .41 Magnum, .44 Magnum, .440 Cor-Bon, and .50 AE Desert Eagles, just the .357 Magnum. They recommended a stout load of AA #9, and at a minimum a 158gr bullet, or even a 180gr bullet.
I've since worked up loads for my gun using 158gr bullets, with stout charges of AA #9, WW296, and Alliant 2400. I won't list the loads online here, but I've cronographed several that approached 1600 fps. They also wreak havoc on the brass, I learned early on that nickel-plated stuff doesn't hold up in a Desert Eagle at those pressures.