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PolarStar CO2 Inserts for UGS and CGS Gas Stock Reviews

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The PolarStar CO2 inserts are manufactured for both the UGS and CGS stocks and have models for both the 12g and 33g disposable CO2 cartridges in either variant. However, the inserts have more uses than just being paired with one of these stocks. Since they are equipped with the same standard ASA threads that are on a HPA tank, they can also be threaded into a conventional regulator to make an extremely compact air rig. 
The only difference between the UGS and CGS inserts is the diameter of the tube. The CGS inserts are narrower since they are designed to fit inside of a CGS's Milspec buffer tube while the UGS inserts are made to the same diameter as a Milspec buffer tube. This means by changing out the stock's rail you are able to reconfigure your UGS from running the standard 13/3000 HPA tank to a low profile, Milspec buffer tube sized cylinder so you can use Milspec AR buttstocks. 
Now, it is commonly known that you should not use CO2 to power an HPA engine since if liquid CO2 gets down-stream of the regulator it can cause a spike in pressure which is unsafe and can damage the sensitive components of the engine. So how is it that we're making something like this? Our CO2 inserts are specifically designed to allow you to safety run your HPA engine off of CO2. 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 or air rig's orientation. 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 33g models accept threaded CO2 cartridges that are commonly used for inflating life vests while the 12g models use the standard 12g cartridges commonly used for Airsoft and Air Guns. The 33g cartridges are simply screwed into the receptacle at the bottom of the insert's bore which pierces the seal to release the CO2. The 12g cartridges are pushed down into the pierce pin using a uniquely designed end cap equipped with a multi-start thread. The multi-start thread consists of four intertwined threads running parallel to one another. Intertwining threads allow the lead distance of a thread to be increased (in this case, an increase of 4X) without changing its pitch. In layman's terms this means it has the strength of a slower thread without sacrificing speed. The cap only needs to be turned 270 degrees (3/4 rotation) from first thread engagement to the point that it pierces the cartridge and seals making changing cartridges an extremely fast and reliable process.
So, you are probably wondering how many shots can you get out of these things? Based on an F2 running at 1.5J w/ .28g through a 6.05x380mm barrel, a 12g will average approximately 180 shots while the 33g will average approximately 500 shots. While these may not be the greatest if your playing style embraces the "accuracy through volume" concept, they are ideal for milsim scenarios where shots counts are lower and realism is higher.
For use with UGS or CGS stocks as well as most common HPA regulators/air rigs which are able to accept 900psi.
All inserts equipped with expansion chamber, anti-siphon system, 5 micron filter and check valve.
UGS requires addition of Milspec Rail (sold separately) before inserts can be used.
Standard ASA threads on all inserts allowing use with standard HPA regulators/air rigs.
Average shot count at 1.5J w/ .28g and 6.05x380mm: 12g = ~180 shots, 33g = ~500 shots
33g models accept threaded CO2 cartridges (p/n 10000332) while the 12g models use the standard 12g cartridges commonly used for Airsoft and Air Guns.
Insert cannot be pressurized before installation into stock/regulator.
CO2 cartridges not included.
PLEASE NOTE: This system will not be compatible with the KWA AEG 3.0 Bodies.
PLEASE NOTE: The Type 1 systems do not have a barb and utilize a push in fitting. See excerpt from the instruction manual below.

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Recently i bought UGS for 13ci tank and now i swich it io 12G CO2 Inserts. Want to test it on next weekend. Also in plan to build VSR10 on bolt system so i want to use CO2 insert there too.
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Posted 1 year ago
Thank you!
Posted 1 year ago
I picked up a USG stock for a DMR build a couple of months ago. I picked up the 33g cartridge adaptor too. the cartridges are smaller and lighter than the 13” bottles, which make carrying the rifle all day a lot easier. Full metal DMR builds are heavier than a standard m4.(I know, right?). So having the lighter setup ,for those days you can’t get back to staging easily, is great. I have the Wolverine Wraith Stock on an M4 build I did a few years back, but I liked the ability to switch back and forth from air to CO2 so much, I picked up a second UGS. The regulator on the P* is a lot easier to use than the Wolverine, and more importantly it has a groove for tournament locking w/ zip ties. The wolverine does not. The Wolverine guys suggest the use of tamper stickers. I made a tournament lock for the Wraith out of a pop can(Soda for you east coasters) and zip ties, but found it a lot harder to deal with the set up, and switched directions with the P*. Pros: makes the gun lighter for longer days. CO2 cartridges are easier to carry than spare bottles. Cons: there’s not a valve on the adaptor, so you cannot remove the adaptor with a cartridge installed. You must expel the CO2 before removing the adaptor from the regulator, (as directed). this is not a big deal at all. the only reason I can imagine needing to remove the adaptor while it's charged, would be to switch between rifles before the cartridge is empty. not a real world problem…
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Posted 2 years ago
Awesome product! Slim lined my stock from a 13ci tank down to a regular sized stock!
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Posted 5 years ago