Never.
One time a while ago, my grandpa and one of his brothers, my great uncle, went through a bottle of Wild Turkey with a 12 pack of Coke. In the process, they got to discussing guns and my uncle pulled out his new Mini-14 Ranch Rifle, only to discover that during storage, the action had, for whatever reason, seized shut and wouldn't budge. He tried yanking it, stomping on it, and all manner of colorful language, but nothing worked. It did draw attention, however, and my brother and I were soon crowded around, trying to ignore the humor in the situation and offer a little sober assistance. I was leaning over the rifle, pointed at the deck, as my uncle fumbled with it, when without warning, he said "Ahhh, [expletive] it," flipped off the safety, and pulled the trigger. Well, 55000 PSI of pressure was enough to unseize the action. But with the left side of my head directly over the compensator, I had an instant headache. My ears rang (for several days, in fact). I was dizzy and disoriented. And slowly, I noticed a .22 caliber hole an inch and a half from my big toe. The message was crystal clear to me--alcohol doesn't belong with guns any more than it belongs with vehicles. So when I drink, I don't operate heavy machinery or power tools, I don't drive, I don't operate firearms--the most dangerous thing I allow myself to pick up is an Xbox controller or a Taco Bell Value Meal.
Besides, it takes very little alcohol to turn my normally reserved self into a completely different creature, abandoning all inhibition, and with a little more alcohol, looking for a fight. I don't always win (rubs lump on head)
I should probably explain that my brother is the wild one, and the alcoholic, so most of the time, I don't drink--I drive and try keep him from getting a mud puddle stomped up his rear end (again, not always successfully). So when I do get a chance to drink, I drink...