GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: vigilandy on January 27, 2017, 01:38:54 AM
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A while back I acquired an inline paintball regulator (air and CO2) with an eBay purchase. Been sitting on it thinking this would be a good chance to try regulating a CO2 tank. My main complaint with CO2 has been the varying POI due to temperature change. If I kept the regulated pressure relatively low (under 850 psi) wouldn't this allow for a huge number of consistent shots at a very wide range of temperatures?
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Always did when I shot Paintball guns on Co2 .... 750/800 PSI set pressure and have at it against the HPA shooters.
sadly in PCP air guns, the 750/800 psi range is very minimalist for all but lower power application in most calibers.
JMO tho ...
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"consistent shots at a very wide range of temperatures"
Depends upon what you consider "wide". Have seen my bulk tank go from 400psi to a little over 1000psi depending upon temperature.
Regulating to 400psi will work under certain circumstances, but overall I have to agree with Motorhead.
That said....can something be built to effectively utilize low pressure...yes indeed.
https://www.youtube.com/watch?v=VfBRbSXM2Wk&t=194s (https://www.youtube.com/watch?v=VfBRbSXM2Wk&t=194s)
Al
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If you aren't power hungry (and if you are willing to regulate at 400 psi, that would probably be the case).... then you can also back off on the hammer spring on a CO2 gun and get the valve operating in the self-regulating mode, just like a PCP.... It is quite possible to get CO2 to shoot nearly constant velocity over a 30*F range of temperature.... like this, done with a 12 gr. CO2 cartridge, .177 cal, with 18" barrel....
(http://i378.photobucket.com/albums/oo221/rsterne/1750%20with%20DPH/WebShotStringsDPH9.jpg) (http://s378.photobucket.com/user/rsterne/media/1750%20with%20DPH/WebShotStringsDPH9.jpg.html)
The three "high power" curves show the normal behaviour of CO2 with temperature, and also the loss of velocity within each string as the gun cools from shot to shot.... The three "low power" strings were shot at 46*F, 62*F, and 75*F, and show a huge increase I shot count (2-3 times as many shots), and a much smaller variation in velocity between temperatures and virtually no cooling effect.... Not only that, the velocity is not that much less than what it was at 46*F anyways, particularly at the end of the string.... CO2 at 46*F is 600 psi, BTW.... so this performance would be similar to regulating at that pressure.... You can do the same thing from 50-80*F, or 60-90*F, it just requires a different hammer spring adjustment.... The higher the temperature range you choose, the higher the pressure, and velocity....
Bob
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I'm in California.... About a hour or two south of Motorhead. Not quite the same temperature swings as you guys see in Canada. It'll all ice and stuff right now right? :D "Cold" weather here is lows in the 30s and highs in the 60s. Summer highs go 100+ though.
I was actually thinking about 600 psi as you suggested Bob. With the HPA reg set at 550 PSI its shooting 14.3gr Crosman pellets at 430 FPS. This is a SSP250 with a modified breech and 18" barrel. No idea what work had been done to it, but it's interesting that in 177 it would shoot about the same speed as yours.
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I have stabilized/encreased temperature by automatic heating inside the QB78 stock but I rader use PCP.
http://forum.gunshop.cz/download/file.php?id=34812&mode=view (http://forum.gunshop.cz/download/file.php?id=34812&mode=view)
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Try a lighter, shorter hammer spring, or an SSG with a light spring.... Get it self-regulating over YOUR required temperature range any you may forget about regulating it.... JMO....
Bob