To call a wizard from Action menu and apply it to a record set just need to set binding_view_types

action.xml

    <record id="action_view_link_mo_to_task" model="ir.actions.act_window">
        <field name="name">Link MO to Task</field>
        <field name="type">ir.actions.act_window</field>
        <field name="res_model">link.mo.to.task</field>
        <field name="view_mode">form</field>
        <field name="target">new</field>
        <field name="binding_model_id" ref="mrp.model_mrp_production"/>
        <field name="binding_view_types">list</field>
    </record>

mos = self.env['mrp.production'].browse(self._context.get('active_ids', []))