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CO2 vs. CA
Posted: Fri Nov 05, 2010 2:32 pm
by Lammy1000
I am ready to take the plunge to precharged target gun(s). I am curious about the pros and cons. The idea of filling from a 20 oz pb tank seems to be the best logistically.
Also, why would one of the 2000 psi dual fuel guns get many more shots for a filled reservoir of co2 than ca? I realize the velocity would be lower on co2, but this is not a concern for my indoor shooting.
Posted: Fri Nov 05, 2010 3:50 pm
by peterz
There's a lot more mass in a tank of CO2 than in the same sized tank of compressed air. The CO2 is in liquid form and denser, actually, than H2O. So there's just more CO2.
No reason at all why the muzzle velocity of a CO2 gun should be lower than that of a similarly designed CA one. In fact, I bet that the velocities are pretty comparable. This is not to say that you cannot buy very, very energetic CA guns, much more so than CO2; you can. But for target rifles and target pistols the performance is much the same.
CO2 vs CA
Posted: Fri Nov 05, 2010 4:09 pm
by BEA
It depends on what you want to do with your shooting. If you are just starting and don't know how deep you will get, you might consider a good used CO2, which you could get for less money, and they are just as accurate. The CO2 is likely more trouble free and cheaper to maintain...not that the CA is unreliable. Due to the higher pressures, the CA may need seal replacements more often, and they have a pressure regulator, which the CO2 does not. This opinion is not ment to start a firestorm. If you have the money, and are serious about shooting, purchase CA because they are the newest technology. If you go to big matches, you will likely not find a CO2 cylinder to refill your cylinders. You will find CA. I shoot CO2 and like it, but if I were younger and was planning on staying in the game, I would go CA. Perhaps not much help, but my thoughts. Good luck.
CO2 vs CA
Posted: Fri Nov 05, 2010 4:13 pm
by BEA
By the way, there is no velocity difference, 500 to 530 fps.
Posted: Fri Nov 05, 2010 4:24 pm
by peterz
Another point: Paintball air is probably not as well dehumidified as the compressed air from a dive shop and meant for human breathing. Could get you into corrosion trouble down the line.
Posted: Fri Nov 05, 2010 4:32 pm
by Lammy1000
I just read that when filling with co2, one is filling liquid co2. I realize the larger weld tanks have dip tubes, but if I use paintball co2 tanks to fill from, should I turn the tank upside down? Also, one of the guns I am looking at does not have a removeable co2 reservoir. Since I can not prechill will this be problematic? Does using co2 as a propellant cause moisture to occur in the bore? Thanks for bearing with these questions. I am a 45 year old shooter who has been at it awhile, but precharged is new to me.
Posted: Fri Nov 05, 2010 4:44 pm
by peterz
but if I use paintball co2 tanks to fill from, should I turn the tank upside down?
May depend on the PB tank. Ask the dealer. Tanks with dip tubes cost a lot more than those w/o, at least where I bought mine. I just invert the 5# tank.
Does using co2 as a propellant cause moisture to occur in the bore?
At least theoretically. The bore chills down from CO2 expansion after several shots, and may drop below the dew point of the air. If so, you get condensation. Store with breech open. Let the gun warm up, and then shoot one felt cleaning pellet.
Posted: Fri Nov 05, 2010 5:27 pm
by Lammy1000
Great info-thank you.
Is a 20 oz paintball tank or an industrial welding tank recommended?
Posted: Fri Nov 05, 2010 8:26 pm
by BEA
I got my CO2 tank at an industrial gas place. It is the type of tank that is used with a portable soda bar. It has a siphon tube in it so that it can be left upright. I have been using the same one so long (1995) that I cannot remember how much it cost. I have never had any corrosion issues with my Walther CPM1.
Posted: Sun Nov 07, 2010 12:20 pm
by Lammy1000
My range in my cellar can be 50 - 60 degrees faranheit in the winter months. Will there be any issus using co2 at these temps?
Posted: Sun Nov 07, 2010 12:43 pm
by Oz
Lammy1000 wrote:My range in my cellar can be 50 - 60 degrees faranheit in the winter months. Will there be any issus using co2 at these temps?
You should probably keep the cylinder a consistent temperature somehow. I stole this from Mac1airgun.com he knows a lot about the properties of CO2/CA.
This is ONLY in regards to the PSI the CO2 creates at these temperatures. Good valve design can compensate for these fluctuations --to a point and keep FPS ranges somewhat reasonable.
The pressure [of CO2] at 45F is 600 PSI. At 65F pressure is 750 PSI. At 85F PSI is 1000 and at 95F PSI is 1250.
Posted: Sun Nov 07, 2010 2:33 pm
by frog5215
If your CO2 tank lacks a siphon tube, you absolutely have to hold it valvedown for a proper fill.
CO2 vs CA
Posted: Sun Nov 07, 2010 9:41 pm
by BEA
It seems like I read somewhere that your cylinder needs to be 20 degrees cooler than your tank in order for them to fill properly. However, if you get the cylinder too cold, it will overfill. With my Walther, I put the cylinders in the fridge, not in the freezer.
Easy fill
Posted: Mon Nov 08, 2010 5:51 am
by Bill177
Here is some good information about using Co2:
http://www.pilkguns.com/co2.shtml
Posted: Tue Nov 09, 2010 12:03 pm
by Rover
This is a topic that has been beaten to death here.
My take on it is that you can find a used top of the line CO2 AP for a lot less money than CA. Performance will be equal and CO2 is very easy to obtain (and cheap).
Posted: Tue Nov 09, 2010 5:16 pm
by Lammy1000
That's refreshing news since I am having issues with start-up costs of CA.
Cost
Posted: Tue Nov 09, 2010 7:57 pm
by Bill177
Regarding shooting cost for Co2 users: I refill my 20# tank every two years. The cost was $16 last year when I had it filled. I typically shoot a couple or three tins a month and usually refill the gun's cylinder after about 130 shots. That works out to $8 a year. It doesn't get much cheaper than that.
When I shoot away from home - I take a couple of filled spare cylinders. I don't use the airlines, so no travel problems.
Posted: Wed Nov 10, 2010 5:34 am
by Lammy1000
My cellar 10 meter range stays a consistent 55 degrees during the winter months. Do you suspect this is an issue w/CO2?
Also, if I choose CA, is a DIN or K/Yoke type valve preferred?
Posted: Wed Nov 10, 2010 6:41 pm
by paw080
Lammy1000 wrote:My cellar 10 meter range stays a consistent 55 degrees during the winter months. Do you suspect this is an issue w/CO2?
Also, if I choose CA, is a DIN or K/Yoke type valve preferred?
Hi Lammy, 55F degrees should not be a problem. I've shot my Steyr LP1-C
in the low 50's for about 7 weeks. I didn't notice any significant impact
change. I've also shot that same LP1-C in 102-103 F degrees, without any
problems. the cold weather was harder on me than the hot weather.
Perhaps the temperature extremes will affect other brand CO2 pistols
differently than my LP1. I also tested my FEG GPM-1s in 100+ degrees,
and they tolerated the heat just fine; I didn't shoot them in temperatures
below 60 degrees however.
TG
Posted: Thu Nov 11, 2010 8:12 am
by jipe
Lammy1000 wrote:My cellar 10 meter range stays a consistent 55 degrees during the winter months. Do you suspect this is an issue w/CO2?
Also, if I choose CA, is a DIN or K/Yoke type valve preferred?
The only problem with CO2 is that big changes of temerature may need an adjustement of the sigths because the velocity is changed. In your case, the temerature is low but constent -> no issue.
For CA, you need a DIN valve on the refilling system (pump, big CA bottle or compressor) because all refill adapters (any brand) have a DIN thread. Note that there are two DIN thread: one for 200bar and one for 300bar. Actually, the thread is teh same but the length of the thread is different to prevent putting a 200bar adapter on a 300bar bottle.
The choice between CO2 and CA depends a lot of the possibilities you have to refill the cylinders. Less and less shooting clubs have CO2 while more and more have CA.
If you want to refill it yourself, check what is easiest/cheapest to find in your area. The price of the refill system must be added to the price of the pistol/rifle.
The main advantage of CA is that it is easier to refill: it is fast, no need to put the cylinder in the freezer, no need to weight the cylinder know how much remain in it and last point, you can be 100% self sufficient if you buy a hand pump. Hand pump is also the only option if you travel by air (cylinders must be emtpy for air travel -> either you find a place to refill after the fligth or you take your pump with you).