It is possible, but then you would have to open the gun, have your loaded ammo be ejected out in order to cock the firing pins to fire. It could be done if the hammers are down, you remove the forearm and barrels, put ammo in the barrels and reassemble......but it would serve no purpose at all.
If you are trying to come up with a way to keep a gun for HD with ammo in it but not cocked, this is not a good idea - load it and use the safety for night time duty and unload in the morning, or load the two barrels and leave the action open so all you need to do is close and move the safety and fire