I used to have a Zabala (made in Spain) 10 gauge side by side with double triggers I bought used in 1980. It would kill from one end and cripple on the other. I used it duck and goose hunting in Eastern Colorado. My buddy Tom named it the "Sky Sweeper". I pulled both triggers at the same time exactly once. There was a flock of geese in a V coming in to Jackson Reservoir (probably too high) and I swung ahead of the lead bird and yanked both triggers. The recoil liked to have screwed me into the ground. The 3rd and fourth geese in line tumbled. One was banded and both ate good, since they'd been spending a lot of time in corn and sunflower fields chowing down on quality food.
I sold the 10 gauge to my roommates brother who killed a doe with a head shot with BB shot at 55 yards the first day he owned it. Still has it too.