As with many paintball players, I am constantly trying to tune my gun to give better performance. Obviously, if one wants an accurate gun the first order of business is to get the gun shooting at a consistent velocity. The normal way to do this is to run HPA. But I live in a small isolated town. HPA is not available for at least 100 miles in any direction. Thus, whatever I do it must involve CO2.
But CO2 really isn't that bad. Provided you are below the critical temperature (88 F), CO2 provides extremely consistent pressure at a given temperature. In fact, you'll never convince me that any regulator will provide a more consistant pressure than just a bottle of CO2 provided that the shooter uses very low rates of fire on a nice spring afternoon (IE, less than 88 F).
But for high rates of fire, CO2 will not provide consistent pressure. As the bottle cools, the pressure delivered to the gun will drop. In addition, a gun utilizing CO2 requires frequent re-chrono'ing throughout the day as the temperature rises and falls. Thus, while "plain" CO2 may provide rock solid performance on paper, it falls far short of this ideal in the real world.
The cure for the real world instabilities associated with CO2 is a regulator. A properly set regulator will provide stable pressure to a gun regardless of rate of fire or weather conditions (within reason).
The consensus seems to be that the only good regulator for CO2 use is the Palmer Stabilizer. But the Stabilizer (in my opinion) fails the ergonomics test. It is (again, opinion) completely unusable as a foregrip due to the placement of the inlet port.
Another good regulator is the WGP Ergo regulator. The ergonomics of this regulator are acceptable and everyone agrees that it has good performance. There is, however, one problem. The Ergo is designed for HPA and the word on the street is that it performs poorly with CO2. I've disected an Ergo and my instincts tell me that this is true - that the Ergo will not deal well with liquid CO2 (I must, however, confess that I've never tested the Ergo on "plain" CO2 but my instincts on such matters tend to be pretty good.).
Then it occurred to me - if I could keep liquid CO2 out of an Ergo, it should perform just as well with CO2 as it performs with HPA. But how can I keep liquid CO2 out of an Ergo?
The obvious solution is an anti-siphon tube but I don't like them. Why not? Because they don't work if you have to borrow a tank for whatever reason.
An expansion chamber would in theory do it too, but in reality won't work as it needs to occupy the same real estate as the Ergo.
Running remotely is a third solution but I'm a serious crawler - I don't want a cable to get caught on every tree branch I crawl over/under.
And then I saw it. The answer. The R-2000 regulator. The R-2000 is a cheap regulator that is designed to screw into an ASA between the gun and your CO2 bottle. I doubted that such a low-cost regulator that was undoubtedly going to see liquid CO2 could maintain a very steady pressure, but that was OK. All I would ask the R-2000 to do was lower the pressure enough to guarentee that liquid CO2 would not be found downstream of the R-2000.
And so I set out to obtain all the necessary pieces and set up my F4-Illustrator. I picked up an Ergo for about $40 on ebay and an R-2000 for about $30 also on ebay. Total cost was about $70 - comparible to the cost of a Palmer Stabilizer.
But how did it work?
At no time was the gun's velocity adjusted.
Notice that this proceedure is designed to establish the gun's performance both before and after a prolonged shootout.
| Before | After | Combined | |
| Avg Velocity | 273.2 | 273.0 | 273.1 |
| Standard Dev | 3.4 | 4.7 | 3.6 |
It should, however, be noted that the gun would hold shots between 270-276 fps (+/- 3 fps) for the majority of the shots. Periodically though, I would get a "flier" that was either high or low (+/- 8 fps). The second group of shots had 2 of these fliers and I believe this to be the cause of the increase in standard deviation. More to the point, if the fliers are removed, the average velocity for the remaining shots fired becomes 272.8 fps with a standard deviation of 2.5 fps. Not bad at all.
I have played around with my F4 in numerous ways over the past year or so. I've tried many things, but this is the best I've yet to see my gun (or any other F4 for that matter) perform. Obviously, I am pleased.
Those who've read my musings concerning the consistency of CO2 vs. HPA may at this point be confused. I have not apparently followed my own advice. This is only partially true. While it is true that I have deviated from the letter of my previous advice, I have not deviated from the engineering principals driving said advice. Call me a lawyer, but I see no contradiction.
PS: Yeah, I know I actually used a CO2000 and not an R-2000. Internally it's the same regulator so the results should hold. I bought the CO2000 because the price was right (ebay, remember?) and I wasn't 100% sure it would work as well as it did. If I had it to do over again, I would indeed get the R-2000.