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What's the most powerful CO2 powered pellet gun?

Discussion in 'Non-Firearm Weapons' started by zahc, Nov 17, 2008.

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  1. zahc

    zahc Member

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    What's the most powerful CO2-powered BB/Pellet gun?


    I was thinking about making a BB gun that took a CO2 tank from a paintball gun, and paintball parts. But then I realized that since BBs are so much smaller in diameter than paintballs, then there might not be enough pressure to get good velocity, at least not without a long barrel. I calculated that the area/mass ratio for paintballs is about 1.5 times what it is for a BB, so to a first approximation I can expect to need 1.5 times the pressure to accelerate a BB to the same velocity as a paintball in the same space of barrel. Paintball markers run as low as 2-300PSI, but only shoot 300fps. If I wanted say 650FPS I would need 900PSI which is all you can get from raw CO2.

    I know the real powerful pellet guns use a spring piston. I know there are CO2 powered BB guns, but I think they only get 700fps at the most out of using raw CO2, and that's with the long barrel. But then I'm not sure if they intentionally throttle using valve dwell in order to get more shots/cartridge. I'm wondering if I used the highest-flow valves etc that I could, how much velocity could I get out of raw CO2 with a BB?

    I figure that using larger BBs doesn't help, because volume scales as R^3 but area scales as R^2.
     
  2. Schofield3

    Schofield3 Member

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    [​IMG]

    You'll shoot your eye out!
     
  3. hso

    hso Moderator Staff Member

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  4. zahc

    zahc Member

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    I'm not interested in buying an air rifle. I'm interested in building a BB gun that uses CO2, and I wanted to know how powerful commercially available CO2 powered air rifles are.
     
  5. hso

    hso Moderator Staff Member

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  6. WardenWolf

    WardenWolf member

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    I have a saying: "Thou shalt not play at any profession whose name ends in the word 'Smith'." That applies to airsmith as well. I play paintball. I know how dangerous CO2 and high pressure air can be, including 12-gram powerlets. You should NOT be screwing around with high pressure unless you REALLY know what you're doing. Don't be stupid.
     
  7. PTK

    PTK Member

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    Take basic precautions, be safe, and double-check all information. Find reputable, published sources for build information if you can. And please, keep us posted, I love seeing homebuilt airguns. :)
     
  8. zahc

    zahc Member

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    I do. This wouldn't be the first one I built. I used to build custom paintball markers, including some pretty novel designs.
     
  9. plumberroy

    plumberroy Member

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  10. colt.45

    colt.45 Member

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    pressure is not the only thing that matters. your calculations are also very wrong.

    the most powerful co2 gun would probably be a modified crosman. some have come close to 800 fps in .22. then again... co2 becomes much more efficient as you increase the bore sise. a modified 9mm crosman 2240 could possibly hit 55 ft lbs.

    wait for my post on airguns.
     
  11. RyanM

    RyanM Member

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    Quackenbush used to make a CO2 powered big bore. .375 caliber, and it would shoot an 84 gr round ball at 600-650 fps. 10-12 shots per fill.
     
  12. elmerfudd

    elmerfudd Member

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    You can take a CO2 gun like a Crosman 22xx or a QB78 and bore out the valve, bore out the transfer port, lighten the valve spring and either add weight to the hammer or install a heavier spring and get some serious gains in velocity. With the 22xx if you install the 2260 barrel that will give you some extra velocity too.

    I've got a QB78 in my gun cabinet that was a buddies project gun. Pretty much all he was interested in was power. I helped him rebarrel it in .25 caliber and that part got done reasonably well, but he butchered the rest of it. I ended up buying the whole thing from him for $25 later on and it was a wreck. I rebuilt it somewhat and with that .25 barrel, a super bored out valve and 1000 PSI of air I can get 40 fpe out of it. I forget which pellets I was getting that with now. I think it was with 35 grain Eun Jins. I only get three shots per charge, with about 2" groups at 50 yards and it sounds like a .22 short.
     
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