I've never done it myself. Honest! I really can't stand the taste of beer, and they don't sell hard cider in cans. So somebody will need to verify this.

I believe shotgunning involves shaking the hell out of a can of beer and then opening it while clamping your mouth over the hole. The idea, I think, being to suck down the whole can without spilling any. Real bright, hmmm?

Cheers!

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"Life is too short for grief. Or regret. Or bullshit." -- Edward Abbey, Vox Clamantis in Deserto