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PolarStar CO2 Gas Stock CGS HPA Stock System (Model: Type 2 / TM Spec Receiver)

ID: 13518 (ACC-HPA-10000535)
PolarStar CO2 Gas Stock CGS HPA Stock System (Model: Type 2 / TM Spec Receiver)
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CO2 Cartridges & HP Spring Not Included
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  • Includes 12g CO2 insert (33g available separately), castle nut, and all mounting hardware
  • Machined from a Milspec AR buffer tube blank
  • Compatible with Milspec AR stocks
  • Convertible between 12g and 33g cartridges through the use of interchangeable CO2 Inserts
  • Average shot count using an F2 at 1.5J w/ .28g and 6.05x380mm: 12g = ~180 shots, 33g = ~500 shots
  • Simple zip-tie lockout/tournament lock
  • Incorporates PolarStar's proven compact regulator design which uses only 2 o-rings, promoting reliability and ease of maintenance
  • Not compatible with Fusion Engine
If you are someone that has always wanted to have the performance and versatility of an HPA system but just couldn't bear the thought of being tethered to an airline or having a tank screwed into the back of your rifle, then the CGS was designed specifically with you in mind. Externally the CGS is manufactured using a real Milspec buffer tube blank which has been modified to conceal an adjustable regulator and CO2 cartridge which allows you to run your HPA system while retaining the same realistic appearance and the use of traditional Milspec buttstocks.

Its integral regulator shares the same internal design as PolarStar's other compact regulators and delivers performance on par with systems twice its size. This regulator has an output pressure range of 40-130psi which is easily adjusted using a 3/32 allen key but can be locked out using a standard chrono zip tie which blocks the adjustment screw. Additionally, if you want to get a little more "omph" out of the regulator, you can install the High Pressure Spring (p/n 10000692)* which boots the maximum output pressure to approximately 200psi.

This regulator is coupled with a removable CO2 insert which is easily installed by sliding the insert into the back of the buffer tube and screwing it into the regulator's ASA threads before being secured with a set screw. This modular design makes the CGS a very versatile system since you are able to swap between two available CO2 Inserts giving you the ability to use either traditional 12g CO2 cartridges or the magnum sized 33g cartridges (p/n 10000332)* for even more shot capacity.

These inserts feature an integral expansion chamber, anti-siphon system, 5 micron filter and check valve to prevent liquid CO2 from entering the regulator regardless of the rifle's orientation and therefore safeguarding the system from any spikes in pressure. As an added benefit, the internal check valve also prevents gases from escaping the expansion chamber while switching out cartridges so as to conserve as much CO2 as possible when performing a "combat reload" and allowing several full-power shots even while when the CO2 cartridge has been removed.

The Type 1 is designed for use with AEG receivers that accept 1-3/16"-16 threaded buffer tubes such as the G&P R3 series. This is where the buffer tube itself threads into the receiver. (Modification of the gearbox is required)

The Type 2 is designed for use with traditional TM Spec M4 series AEG receives. This is where the buffer tube slides onto a stock tail on the back of the receiver and is secured by a bolt. (Modification of the receiver and gearbox is required)

In order to offer the most realistic experience possible, the CGS buffer tube is machined from the same blank, using the same processes, and follows the same specifications as a Milspec buffer tube. This means the CGS is compatible with all Milspec AR stocks, but may not be compatible with some AEG stocks due to the lack of standardization between manufacturers.

If there is a particular AEG stock that you would like to use and it will not fit on a standard Milspec buffer tube, please see the Universal Gas Stock. The UGS has the same CO2 options as the CGS, but in a modular configuration that has been designed to fit all Milspec stocks as well as most AEG stocks.

Manufacturer: PolarStar


Min Output Pressure: 40 PSI
Max Output Pressure: 130 PSI (~200 PSI with HP Spring, p/n 10000692)*
Max Input Pressure: 900 PSI
Outputs: Interfaces w/ Airline (6mm OD x 4mm ID)
Compatibility: For use with Tokyo Marui spec Airsoft M4 receivers
Material: Aluminum, Brass
Package Includes: Stock System, 12g CO2 Insert

About PolarStar

PolarStar Precision Airsoft was formed in January 2009 to fill a need for high quality, precision manufactured airsoft components designed for performance and longevity.The 2011 release of the patented Fusion Engine HPA system marked a change in direction for PolarStar. The focus shifted from developing upgrade components within the constraints of existing systems to developing innovative HPA systems and accessories which replace the aging AEG technology.PolarStar Airsoft is a division of PolarStar Engineering & Machine (PSE&M), a unique blend of tenured American toolmakers and a full service CAE/CAD/CAM (Computer Aided Engineering, Design, and Manufacturing), special crafts machine shop keeping alive our proud manufacturing heritage of Made in the USA. Founded in 1997, PSE&M began by servicing the automotive racing industry through the design and producing systems and components from art to part. Operating under the auspices of the Delaware Association of Professional Engineers, we retain a Professional Engineer (P.E.) on staff to ensure and certify all design and engineering standards are met. In addition to our own product line, PolarStar also offers engineering and manufacturing services tailored to the airsoft industry.

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