No. The 12 dmg shotguns are already too broken and it makes people camp in their base in order to easily 2 shot players that go in. They have only 2 shots for a reason, because they can 2 shot players. Adding a stun would be unbearable.
If you think rockets are useless in this game, you should try to change the rocket launchers, not add rocket launcher features into shotguns.
