My FN-Browning o/u shoots both bbls. in 1 hole at 50 m. It had to be re-regulated when I had it scoped and I assisted when the operation took place. My gunmaker was very cooperative (and patient) for he had to de-, resolder the bbls. several times + move the wedge + test-shoot until I was satisfied. BTW, it proves "they" can do it when they work at it...