Ah, Chongo -- there isn't any safety on a revolver, and if you're using a M1911A1 or similar there are several safeties, including the one in the grip. If you're sleeping with it locked and cocked and one up the spout under your pillow, turning in your sleep could cause you to awaken prematurely and quickly or never awaken at all.

Unless...you don't keep a Tommy gun under your pillow, do you? The drum mag might make it uncomfortable to sleep on, but the flat mag would probably permit it. I'd use two pillows, just for comfort, myself.

Why don't you just keep it in a holster along the side of the mattress? Lots safer and quicker to get to, too.