CO2 Modifications
Printed From: Kiwi Airgunners
Category: General
Forum Name: Flub's General Discussion
Forum Description: General discussion goes in here.
URL: www.kiwiairgunners.co.nz/forum_posts.asp?TID=1073
Printed Date: 03 Nov 2025 at 6:31pm
Software Version: Web Wiz Forums 10.14 - http://www.webwizforums.com
Topic: CO2 Modifications
Posted By: GOODold308
Subject: CO2 Modifications
Date Posted: 28 Aug 2024 at 2:14pm
|
Hi everyone I'm new here. I am thinking about picking up a Air Chief CR600W and have seen a few mods for them like to port job and a bulk fill tank. My question is how far can I go with modifying one and can I use G1/2-14 threads as I have been looking into regulated CO2 and would like to do that so I can turn down the pressure if shooting bird indoors or up for shooting rabbits and also to improve the standard deviation in velocity. I want to keep it CO2 and don't want to cross the like of it being classed as a PCP. I am an engineer by trade and like to tinker with things and a CR600W is the latest project I'm wanting to undertake. Any input is much appreciated. Cheers |
Replies:
Posted By: kruzaroad
Date Posted: 28 Aug 2024 at 2:33pm
|
How's it 308. Welcome aboard. I'm not qualified to answer your question, just welcoming you. 👍 |
Posted By: RangerPete
Date Posted: 28 Aug 2024 at 5:19pm
|
Me too, no experiance with CO2, but welcome to the forum. Post some pics of the gun you get and your modifications that u end up performing. Pete. ------------- Walk quietly, but carry a big stick. |
Posted By: Pauly5
Date Posted: 29 Aug 2024 at 1:29am
|
G'day, welcome here. I am very confident that as long as you keep it powered by CO2, you will be totally legal. The arms acts talks about high pressure air when refering to "specially dangerous" airguns. Many have bulk filled these guns and other guns such as the crosman 2250, which will give you many more shots without running foul of the law. You can even buy a CO2 powered arrow gun without a license. So with that out of the way, it'd be great to see your project here if you want to post a few photos. When you say you want to fit a regulator, do you mean a method of adjusting power such as a transfer port that can be opened up or closed? Another method could be hammer spring adjustment?
|
Posted By: jwabfrog
Date Posted: 29 Aug 2024 at 3:12am
|
Hi 308, welcome to the forum. A common mod to increase power on the air chiefs is to drill out the transfer ports and increase hammer tension so engineering means of adjusting either will give you the power adjustability you're looking for. Have a look at Pauly's thread on modifiying this gun. He managed to extract a significant power increase with clever mods around the pellet probe from memory. I have parts for sale for the PCP version of the air chief if you want any of these for your tinkering (air reservoir etc might be useful). The basic design of both the PCP and CO2 guns is identical so parts are interchangeable. Lastly have a look at the parts diagrams for Air Arms PCP rifles - these have a power wheel rotates a valve to opens and close the transfer port which might be food for your redesign.
|
Posted By: Pauly5
Date Posted: 29 Aug 2024 at 4:48am
|
This is the thread, but it is for the 362 pumper, but certainly applies to the CO2. http://www.kiwiairgunners.co.nz/forum_posts.asp?TID=806&PN=1 Is that the one you mean jwabfrog?
|
Posted By: jwabfrog
Date Posted: 29 Aug 2024 at 5:00am
| Yep that was the thread Paul |
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 6:43am
|
Thanks for the welcomes and information. I have a lot of food for thought now. I have only read these 2 posts about mods for the cr600. http://www.kiwiairgunners.co.nz/forum_posts.asp?TID=607 https://www.nzhuntingandshooting.co.nz/f15/air-chief-22-cr600w-co2-77769/ I'm still very sceptical on what I can get way with as it seems like I could basically build a FX M3 but run it on C02 but if that was the case a person would be able to by a M3 and 88gram CO2 cylinder with adapter to G1/2-14 and then adapter G1/2-14 to M18x1.5 I was originally planning on making a drop block reg and plenum that and take the 88g cylinder I was also going to try make an adjustable hammer spring too but now I am re thinking my hole plan. I am about to get off lunch so will add more this afternoon. |
Posted By: Pauly5
Date Posted: 29 Aug 2024 at 6:57am
|
There are a few rifles available now that you can very easily adapt from CO2 to HPA. If you were to adapt an HPA to CO2, I wouldn't touch it unless I had my fal as it would have been designed as an HPA. But if you modify a CO2 to accept a bigger CO2 tank, it is still only CO2 and doesn't require a fal. If you modify a CO2 to use HPA, you turn it into a restricted gun requiring fal. The law is pretty clear, but for your own reasons you are being cautious, which is admirable. Take the CR600W and Airchief pcp as an example. They are basically the same, and there's the walther pcp/CO2 gun that is bascically the same apart from power type. Although reasonably easy to convert, if it's CO2, no fal. Please don't think i'm arguing with you, I just want to see another project thread.
|
Posted By: kruzaroad
Date Posted: 29 Aug 2024 at 6:57am
|
I was looking at a descusion from earlier on, and simple matter of co2 is it can't reach the pressures that a pcp needs to operate at dangerous fpe.(for people) I think this the whole reason it doesn't need a licence. So yeah you could convert your pcp. However your make and model of pcp would still come up as a licence needed as its not the way gun comes. Cops would take it off you and do thier who-ha, costing you time and money, possibly your fal till you got it sorted. This speculation on my behalf only. |
Posted By: jwabfrog
Date Posted: 29 Aug 2024 at 10:11am
| Good points from Pauly and Kruza - do not play with any form of HPA / PCP unless you have a current firearms license. |
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 10:46am
|
jwabfrog correct. What I was asking is there any fitting types I can't use like G1/2-14 or M18x1.5 as those are common fittings on pcp systems. I went a picked up a cr600w today along with a 88g co2 cylinder and co2 to G1/2-14 (paintball) adapter and they guys at guncity were sweet as with it and we agreed it's fine as long it doesn't run hpa. I'm not sure how to upload photos but once I figure it out I will post one but maybe in a different post. 
|
Posted By: nunga
Date Posted: 29 Aug 2024 at 11:37am
|
You can upload photos using the "post reply" button ( bottom and top left side of the screen). the option is not available in the quick reply box that most people use. I will be upgrading the forum over the weekend so hopefully it will be a bit easier to use once im done. Welcome to the forum. ------------- 2nd place HP springer - WFTF World Championships 2014 |
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 11:47am
| Thanks I read your reply after probably doing it the long way. I haven't been on any forums in maybe 10 years so I'm a bit rust. I ended up doing upload then open image and copy url then you the [IMG]url[IMG] thing. |
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 12:57pm
|
Here is the adapter I talked about earlier Guncity call it a Air Source 88G Adapter CO2 Paintball. It goes from M16x1.5 to G1/2-14. The reason I asked is I plan on having the main feed in G1/2 as it has a common o ring size so easy to get replacements and easily adapted to any cylinder size. I will strip down the rifle and get some measurements and I will come up with more of a plane for what I want to do, build and lower valve block or just cut down the lower tube. I have also been thinking about a Gamo C.A.T trigger and if I can adapt one to work.  
|
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 1:59pm
|
Thanks Paul for the input. I am wanting to do a regulator to plenum as CO2 is very sensitive to temperature and I was reading that a regulated plenum can help with shot consistency but I may have to regulate to 600psi in the plenum. The regulator for the plenum can help control power and I was going to try make an adjustable hammer spring and I like your idea of an adjustable transfer port. I want to be able to turn down the power so I don't get pass through shots on birds while still being useful for rabbits during the day that's the main reason for it. |
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 2:02pm
|
jwabfrog Thank you for this it is very helpful I had a quick look at the thread I do like that idea and also interested how it will behave with CO2 as the pressure drops as it cools. I can't pm you until I get 40 points so not sure how long that will take but I am interested in some parts mainly the valve as I can't find anything about it online. |
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 2:30pm
|
kruzaroad seems logical I just wasn't sure if there was certain criteria for a air rifle to be labeled pcp under the arms act. CO2 is technically pre charger pneumatic due to the definition of the word pneumatic. Maybe HPA rather than PCP should be used. I am going to assume it's only classed as PCP when it's manufactured and imported like someone pointed out the Air Chief uses the same platform for CO2 and HPA but the CO2 version has a cut out in the tube so it can't be pressurized and can visibly see the CO2 canister. |
Posted By: GOODold308
Date Posted: 29 Aug 2024 at 3:16pm
Is there a particular model for the power wheel I found this site and there is heaps on there. https://twchambers.co.uk/airgun-spares/air-arms/ |
jwabfrog wrote:Posted By: jwabfrog
Date Posted: 30 Aug 2024 at 3:14am
|
https://spares.bagnallandkirkwood.co.uk/product/air-arms-fac-high-power-power-adjuster-knob-s508/
Funny, the spares diagrams don't generally show this part. It's just a shaft with a hole drilled through it. Limits the rate gas can travel through transfer port into the barrel.
|
Posted By: GOODold308
Date Posted: 31 Aug 2024 at 4:52am
|
jwabfrog thanks for that it's a super simple design I'll see if I can make something like this work I think it will probably need some sort of detent to stop it free spinning. I have been thinking about those spare parts you have and I'm keen to grab them off you it will make it easier for me to do a proof of concept build. I am just working out how many CC's I need the plenum to be and I will be able to cut down the PR900 pressure tube to use as the plenum. Will try PM you. |
Posted By: jwabfrog
Date Posted: 31 Aug 2024 at 4:55am
| I have PM'd you 308, check your inbox? |
Posted By: GOODold308
Date Posted: 31 Aug 2024 at 5:05am
| I don't know if I'm blind or stupid but I can't find an inbox and haven't received an email saying I have a PM |
Posted By: kruzaroad
Date Posted: 31 Aug 2024 at 5:38am
| Push the zero new messages at top of page that should take you to the options for mail |
Posted By: GOODold308
Date Posted: 31 Aug 2024 at 5:43am
 I honestly can't find anything sorry haven't used forums in a long time I mostly use reddit and discord these days |
Posted By: kruzaroad
Date Posted: 31 Aug 2024 at 5:53am
That would be because it doesn't look like its there.  Try the member control panel and see if it gets you somewhere. If not, I'm not sure. Does some wierd things at times. Nunga's upgrading the site this weekend. |
Posted By: GOODold308
Date Posted: 31 Aug 2024 at 7:12am
| When I registered it said I had to get 40 points before I can PM so maybe that's why it's not there. I am not sure how long it takes to get 40 points or what I have to do to get points. |
Posted By: jwabfrog
Date Posted: 31 Aug 2024 at 8:03am
|
Deleted |
Posted By: nunga
Date Posted: 31 Aug 2024 at 9:52am
I will fix that for you now. that was a new feature i added a couple of weeks ago because of the scam users were signing up and trying to scam people. I will change your group status and you will have that option. ------------- 2nd place HP springer - WFTF World Championships 2014 |
Posted By: nunga
Date Posted: 31 Aug 2024 at 9:55am
|
You should be able to see New Messages now ------------- 2nd place HP springer - WFTF World Championships 2014 |
Posted By: GOODold308
Date Posted: 31 Aug 2024 at 10:09am
I did read that people were using random emails and user names. Thanks for sorting that. |