Plutonium

Thanks man, i'll try again!

Hey guys, first of all, sorry if I'm writing in the wrong section, I'm new here so I don't really know well where things go.

I was playing mob of the dead and trying do make the Blundergat, but when I threw the Hell's Receiver at the skulls, nothing happened. I did it to the 5 skulls thinking it would work anyway but it didn't. I'd like to know if it is possible to be done or not.

Same thing with the Hell's Redeemer, after I killed the zombies in the roof using the Hell's Receiver and threw it on the hole, it just came back to me, instead of upgrading.