Stan I know constrictions do not directly translate into patterns but that is IC type chokes in a .410. I could see them being a light modified in use, but not much tighter than that.

The old double .410 I use, that was my late uncles, is choked .005, skeet and .030+ laser beam XXF. Worse it has trigger pulls of about 8 pounds and 3 1/2 pounds. It was choked that way and triggers altered that way by my late uncle. I suspect he never put the safety on when hunting alone and would rest his finger on the heavy first trigger but this is just a guess. I do remember him shooting the oddest triple one morning. A double on a covey flush, then as fast as he could reload he shot a cotton tail that made a dash for it.