I have a vague recollection that this "beehive" round was developed by a small company in the USA several years ago as a novelty round rather than a serious piece of combat ordnance.
Doing a quick check, it would seem that it might have been made as a way to get more variety in 40mm ammo available to US civilians (destructive rounds are apparently very expensive, if they can be found for sale at all).
Also available in 10-rd capacity (with some good images of the whole contraption)
http://www.freewebs.com/grog/10%2022%20review.htm
https://www.everydaynodaysoff.com/20...-22lr-adapter/