I have a single non-selective trigger on my William Evans 12 bore BLE, his patent, and so far it has not given any trouble. The gun is bored IC/IC for driven game. I would prefer double triggers but could not resist, buying it, as it is such an elegant gun. BHugh Lomas blacked the barrels for me and removed and atraightned the top rib and di a super job, I would recomment Hugh highly.
Mike