Tokyo Marui recently announced their new M870 gas powered shotgun. Using a new system that is capable of firing 3 or 6 rounds with every shot, this thing has the potential to revolutionize the shotgun market.
It uses a removable gas tank stored in the full stock and is reportedly capable of firing 100 rounds between gas fills. It’s even compatible with the old TM 30 round shotgun shell magazines. I’m looking forward to seeing this thing on the market soon!