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Air Gun Home Forum Index » General Air Gun Questions and Topics » Moderating CO2 / Pneumatics    View previous topic :: View next topic  Moderating CO2 / Pneumatics   Posted: Fri Oct 05, 2007 1:42 pm logunmk1 New Member Joined: 11 Sep 2007 Posts: 6 Location: Sale, Cheshire, U.K Can anyone explain why very effective sound moderators that quiten down pre charged pneumatics to a whisper have little or no effect on much less powerful Co2 guns... Is it anything to do with Co2 being a gas?? The effect or lack of it is amazing Can anyone explain..... Come on Eric!! Garry   Posted: Fri Oct 05, 2007 2:09 pm Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND The differance is that PCPs have there pressure chamber filled with air in a compressed state, on a Co2 gun the gas starts off in a pressure chamber as a liquid and expands into a gas as it is required, PCP tend to run at higher pressure than Co2, apart from that silencing either is the same and both can be silenced right down to a wisper, even very low powered Co2. by the way both Co2 and Air are gases Al   Posted: Fri Oct 05, 2007 2:25 pm logunmk1 New Member Joined: 11 Sep 2007 Posts: 6 Location: Sale, Cheshire, U.K Thanks Al, really appreciate you explaining that. Can you explain why my favourite moderator that I buy for all my guns that is so effective (all PCP) is absolutly useless when fitted to a crosman 1077 Co2 gun. makes no difference whatsoever Garry   Posted: Fri Oct 05, 2007 3:41 pm Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND Hi logunmk1 The reason it does not work is probably because it not tuned for the pressure levels of the Co2 airgun you are using. The moderator you are using is probably made for PCP rifles which run at higher volocity than Co2, multi chamber silencers work better with Hi-pressure air, for Co2 you need less chambers in a slightly diffrent layout in the silencer but about the same volume. What make of silencer are you using. Al   Posted: Sat Oct 06, 2007 2:14 am logunmk1 New Member Joined: 11 Sep 2007 Posts: 6 Location: Sale, Cheshire, U.K Hi Al Weihrauch silencers seem to be the quietest in the UK from all the others, loguns etc that I have tried Thanks for the tip on multi chambers Al Best Garry   Posted: Sat Oct 06, 2007 2:16 am logunmk1 New Member Joined: 11 Sep 2007 Posts: 6 Location: Sale, Cheshire, U.K Hi Al What layout would you suggest in the chanmbers Thanks Garry   Posted: Sat Oct 06, 2007 3:23 am 23ib0d0n Moderator Joined: 21 May 2007 Posts: 757 For co2, no chambers, just a moderator body that can contain the gas. My Crooked Barn 2240 featherweight only 'clicks' the valve open, no other noise until the 14.3 grain 570f/s mv pellet impacts.   Posted: Sat Oct 06, 2007 4:11 am Alstone Moderator & Site Supporter Joined: 01 Mar 2007 Posts: 4139 Location: Linconshire, ENGLAND logunmk1 wrote: Hi Al What layout would you suggest in the chanmbers Thanks Garry Hi Garry As 23ib0d0n says "no chambers for Co2 just enough volume to contain the gas", but I find that on some guns the moderator is to large, so I generally make the first chamber half the volume then the second chamber split in two, for .177 the hole size needs to be 5.5mm and for .22, 6.5mm. Have a look at this, the baffels are removeable so you can make up any configuration you like. http://www.airgunhome.com/agforum/viewtopic.php?t=372&postdays=0&postorder=asc&start=15 Al   Posted: Sat Oct 06, 2007 1:00 pm logunmk1 New Member Joined: 11 Sep 2007 Posts: 6 Location: Sale, Cheshire, U.K Thanks a Bunch Al TopMan Best Garry Moderating CO2 / Pneumatics     Air Gun Home Forum Index » General Air Gun Questions and Topics You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum All times are GMT - 5 Hours   Page 1 of 1   All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First  Select a forum Main Forums----------------AirGunHome Q&AGeneral Air Gun Questions and TopicsPicture GalleryTarget Shooting: Casual, Fun and CompetitionHunting, Pest Control, Varminting People/Events/Airgun Issue Discussion----------------Introduce YourselfThe BS TopicClubs/Events/Regional/Political Airgun Issues Maintenance, Modification and Reviews----------------RiflesPistolsAntique, Collector and Novelty AirgunsBB GunsPellets/AmmoOpticsAccessoriesAirgun Smithing Buy, Sell or Trade Forums----------------For SaleWant to Buy   Note: If you are seeing "Please enter your username and password to log in." Your browser cookies have been reset or you need to register to access the topic in question. Use the 'Register' button near the top left of this page. Click Here for AirGunHome.com Main Page Powered by phpBB © 2001-2004 phpBB Group Partial Styling Supplied by Vjacheslav Trushkin Themes Database.