Author Topic: CO2 powered airgun  (Read 6620 times)

Offline cfellows

  • Sr. Member
  • ****
  • Posts: 305
CO2 powered airgun
« on: May 11, 2008, 12:59:04 PM »
Hope this qualifies as ballistics.  This is a CO2 airgun I built from scratch.  It has easily interchangeable barrels, the most powerful being a .25 caliber Lothar Walther.  It will shoot a .25 caliber, 27 grain pellet at about 570 fps with FPE approaching 20.  The CO2 reservoir is a 1" OD stainless steel pipe that's back of the breech.  I get about 20 shots per fill.  I also have .22 caliber and .177 caliber Crosman barrels for it.

Here's a picture:



And a video (I'm not really as big a sourpuss as the video implies):

http://youtube.com/watch?v=1n-EXv5lLbE

Chuck

Offline zeusrekning

  • Madmodder Committee
  • Jr. Member
  • *****
  • Posts: 74
Re: CO2 powered airgun
« Reply #1 on: May 11, 2008, 02:05:44 PM »
Darn Cuck, that you in the video? You like like some cat really pissed you off :) I would love to have one of those. Is there a way to get the FPS up? And what is FPE?
Tim

Offline cfellows

  • Sr. Member
  • ****
  • Posts: 305
Re: CO2 powered airgun
« Reply #2 on: May 11, 2008, 03:56:51 PM »
Darn Cuck, that you in the video? You like like some cat really pissed you off :) I would love to have one of those. Is there a way to get the FPS up? And what is FPE?
Tim

Yeah, that's me.  I'm just a little camera shy... trying to focus on not drooling or picking my nose!  ;D

Feet per second is more or less determined by the weight of the pellet and the pressure of the CO2 or air or whatever.  CO2, at 80 degrees fahrenheit, has a pressure of about 900 pounds per square inch.

With a .22 caliber, 7 grain pellet, I get about 700 FPS and with a .177 caliber, 4 grain pellet, I probably get close to 800 FPS.  Point is, the more the pellet weighs, the less feet per second you you need to get the same "kill" power.  Of course, with high feet per second, you get a flatter trajectory. 

FPE is foot pounds of energy and that really determines the overall power of the airgun.  20 FPE is decent for an air gun, although some commercial models of high pressure airguns (3000 lbs per square in) get 45 FPE or more.  By comparison, a .22 caliber long rifle rimfire gets around 130 FPE.  The legal maximum FPE for an airgun in the UK is 12 FPE.

Airguns are a fascinating subject.  If you want some interesting reading, go to http://www.glbarnes.com.  This fellow makes custom airguns, to the tune of $2500 apiece.  Some of his airguns are as powerful as a .357 magnum.  He does really fine work.

Chuck

Offline Brass_Machine

  • Administrator
  • Hero Member
  • *****
  • Posts: 5203
  • Country: us
Re: CO2 powered airgun
« Reply #3 on: May 11, 2008, 04:12:12 PM »
WoW! That is cool as hell. One day I will make something like that. Very very cool. Did you build from plans or is that your own design?

Eric
Science is fun.

We're all mad here. I'm mad. You're mad.

Offline cfellows

  • Sr. Member
  • ****
  • Posts: 305
Re: CO2 powered airgun
« Reply #4 on: May 11, 2008, 04:29:19 PM »
WoW! That is cool as hell. One day I will make something like that. Very very cool. Did you build from plans or is that your own design?

Eric

It's my own design, although it's based loosely on a model produced by Gunpower called a Stealth.