10-Hole Hero:
The Barrel Vent
UNIQUE DETAILS OF THE 10-HOLE HERO PULSE RIFLE BARREL VENT
fig. 1: "10-hole" barrel vent on the top, "8-hole" barrel vent on the bottom.
First and foremost, the name "10-Hole Hero" originated from the fact that this Pulse Rifle has a special barrel vent with 10 vertical slots/holes in it, as opposed to the 8 holes the rest of the Hero Pulse Rifles have (see fig. 1).
The barrel vent of the 10-Hole Hero also has a rectangular milled out area behind these slots/holes, on the other Hero Pulse Rifles, the milled out area is circular. Also, the recess around the slots/holes has a more squared off rear end on the 10-Hole Hero vent, on the other Pulse Rifles, it is rounded.
The barrel vent differences are the easiest way to differentiate the 10-Hole Hero Rifle from the other Pulse Rifles when watching the movie. It is believed that these details were changed on the later Pulse Rifles in order to reduce machining costs.
The differences don't stop there:
The barrel vents of all Hero Pulse Rifles were a single part (i.e. the "front triangle" was part of the barrel vent and never a separate piece), but the area between the vent section and the "triangle" section was milled down on the other Hero Pulse Rifles, whereas on the 10-Hole Hero Pulse Rifle, it does retain the shape of the slots next to it (see fig. 1).
While the "front triangle" part on the other Hero Pulse Rifles has a distinct triangular shape (like the vent itself), on the 10-Hole Hero Rifle, it is much more curved (see fig. 2).
Lastly, the 8-Hole barrel vents had a sling loop welded to them, while the sling was simply attached to the slots of the 10-Hole barrel vent.
fig. 2: Front of the barrel vent is more curved on the 10-hole Hero Rifle (left) and more triangular on the 8-hole Hero Rifles (right).
The barrel vent on the 10-Hole Hero is secured to the SPAS cage by either a countersunk screw or a countersunk lens head screw that is not completely "countersunk". It sticks out a bit and is not flush with the barrel vent (see fig. 3).
Bug Stomper's theory is that a nut was welded to the Remington 870 barrel which allowed this screw to attach directly to the 870 barrel, adding a secure connection between barrel vent, SPAS cage and barrel.
This theory is supported by this picture which seemingly shows the disassembled "Delta" Pulse Rifle. An unusual "lug" can be seen on the Remington barrel, assumed to be a nut to secure the screw onto the barrel.
fig. 3: Front of the 10-Hole Hero Pulse Rifle, with changes to hue and saturation, to show the protruding screw below the barrel.
Using this theory as a starting point, it is my theory that this accounts for the pushed-back position of the barrel vent in the elevator and "queen chamber" scenes.
Judging from the screenshot in fig. 4 as well as the images of the Delta Pulse Rifle, the screw securing the barrel vent likely went through the front slot on the top of the SPAS cage.
It is possible that the nut on the Remington barrel came loose with time, and this would have allowed the barrel vent to travel back the whole length of the slot on top of the SPAS cage (about 26mm, a little more than an inch), thus resulting in the barrel vent being pushed back while all other components remained in place.
fig. 4: The protruding screw in the barrel vent (below the barrel) as seen in the scene where they discuss the fate of Burke.
The barrel vent as well as the shoulder stock are made from 40mx40mm steel square tube with a wall thickness of 3mm (credit to Bug Stomper for this information). After milling out the slots, the barrel vent/front triangle was then bent giving it a quite characteristic shape. Finally the barrel support tube and (in case of the 8 hole version) the sling loop were welded to the barrel vent.
Based on the excellent plans by Bug Stomper, I have created the barrel vent in Fusion 3D and am offering it for download below. There are two versions: The barrel vent how it looks in its final, bent form, and the barrel vent without the bends to allow milling the slots and indents into the square tube.
