Maybe not four, but if you fly high enough (some 12 000 ft.) and are fast enough, you can easily have enough time to pickle three GBU-38s one after another in one run. Zoom TGP so that you can see the target and designate it. Pickle the first one as soon as you see the "MAN REL". If you want, you can move the TGP cursor a bit and pickle again. And again. You have to be fast with your pickle button. But not too fast (-> ABORTED).