At the Industry Day Range, Standard Manufacturing has a giant Semi Truck RV and a tent with some new products. They are coming out with a small pocket pistol called the VolleyFire. It is reminiscent of the old Mossberg Brownie. The breech-loading style of the VolleyFire is almost identical down to the top latch mechanism.
Where the Brownie and VolleyFire differ is in capacity and that the VolleyFire fires two rounds at a time.
It has six barrels and when the trigger is pressed, there are two firing pins that hit the bullets at opposing ends of the barrel cluster. So it fires two rounds simultaneously. When you reset and pull the trigger, the firing pins rotate to the next pair of bullets.
I am not sure how this is not classified as a machine gun. I thought machine guns are defined when multiple rounds are fired with a single trigger pull. I recall the double barreled 1911 had the same issue when it was originally designed with a single trigger. So they had to redesign it with two triggers that are linked. Look at side by side shotguns or over under shotguns. They have two distinct barrels and chambers. And yet you do not have a shotgun with a single trigger that can fire both rounds simultaneously.
At the moment the VolleyFire will come out in .25acp and they said they have a .22WMR version as well.