They can There are lots of things that can be done but perhaps ought not.
Those bullets will not obturate at all, and will not completely fill the grooves of the rifle, so there will be some blow-by, further mitigating velocity. The additional resistance of the copper jacket won't help either. Meanwhile, these are meant for the 50 AE, delivering @1400 fps muzzle velocity. There will be zero expansion at the velocities delivered from a lightly charged front stuffer.
A hard cast lead bullet at .500 would deliver essentially the exact same performance. A pure lead (BHN 6-8) .500 bullet would be far more effective up to 1500 fps, above which a BHN 10-12 bullet would probably be more suitable.