HOWTO make headphones out of old bullets

Got some extra .40 cal casings kicking around and want to cosplay the scene in the Dark Tower books where the gunslingers stick bullets in their ears to block out the siren call of the "thinny?"

This awkwardly presented GIF HOWTO's got you covered. What's that? I can't hear you, I've got bullets in my ears!

Creating headphones from bullets [Gallowboob/Reddit]