Beretta skeet chokes have a small amount of constriction and then a big flare at the end. They used to make their fixed choke skeet guns this way and their "European" skeet tubes in 12 and 20 gauge are cut this way. They throw beautiful patterns from 15 to 25 yards. My 20 gauge flush skeet tubes have 0.012" of flare. I don't know how they work, but they do.
Regards,
Jeff

"We are men of action. Lies do not become us."
Wesley