UltimateInline
Mark III - Commando






Specs:
-Caliber: 6mm (airsoft)
-Magazine: 1500 rounds
-Barrel: 10" stock, 17" optional
-Velocity: Adjustable 200-320 FPS
-Rate of fire: 90RPS at 100 PSI CO2
-Length: 21" (only one inch longer than a P90)




This BBMG is a commissioned piece for use primarily in close-quarters room clearing, with the possibility of quickly upgrading to a longer barrel length for medium-distance support roles. Due to the extremely high rate of fire, a BBMG in a close-quarters engagement must be strictly limited to meet safety requirements; many considerations were taken into account to ensure that the device will not be more dangerous than the typical stock airsoft gun.


To limit the danger of injury during a close-quarters engagement, the user must not use BBs weighing more than .12 grams, the lightest variety available, to minimize the amount of energy that can be stored in each BB. This limitation can actually help boost the realism factor of the device, as flame-colored red and yellow BBs are typically only found in .12g, not the .20g and heavier weights that the UI Mark II requires. Secondly, the use of a Kobalt CO2 system lets the user very easily and precisely maintain a low operating pressure, decreasing the velocity (and thus energy) of the BBs.


Clearly, the gun has an "unfinished" look; without any painting, mounting rails, or other accessories, it does look somewhat plain compared to my other creations. I intentionally left it like this because, as a commissioned work, I'm leaving it to its new owner to customize. As soon as he puts the finishing touches on it, I'll update this page. Until then, it's in his capable hands to complete as he sees fit.


The chamber is of similar length to the original UltimateInline Mark I, though both the stock and the trigger assembly are brand-new designs. The stock was greatly simplified from the previous designs to minimize space; the new design uses a rodless spring piston with the buffer spring attached directly to the piston face. Although this makes attachment of the stock somewhat more difficult after reloading (the spring wobbles around, not wanting to keep put), it does not affect the gun's reliability. This decrease in reloading speed is acceptable given the nature and purpose of this BBMG, to quickly sweep a room with overwhelming firepower. If 1500 rounds cannot successfully accomplish that task, then the operator should reconsider his plan of attack.


To help with gas consumption -an especially important characteristic given the limited amount of CO2 the operator can carry- the trigger group was redesigned. Unlike the high-flow pressure washer handle, a miniature pushbutton valve with 1/8" NPT inlet/outlet is used, seated inside a spare L85 grip bought from Nashville Airsoft. One added benefit of this redesign is a noteworthy increase in the trigger response time: this valve is significantly more sensitive than the pressure washer handle, so the time between the initiation of trigger pull and the first BB leaving the barrel is noticeably shorter. This improvement is analogous to the introduction of MOSFET triggers in AEGs. A short ring of 2" PVC coupling is used to reinforce the junction of the valve outlet and vortex inlet, also serving as a possible attachment point in the future for a picatinny or weaver rail running from the camlocks on forward.




More Pictures:


The Muzzle

A closeup of the stock and plunger

A view down the chamber from the rear

The whole gun, from the side

A closeup on the chamber




Videos:

all images, text, and other content copyright 2006 John Shell, John@NeoSpud.com