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Thread: Air Rifle Question

  1. #1
    Join Date
    Apr 2006
    Posts
    10

    Default Air Rifle Question

    I have an older Slavia 630 break barrel air rifle in .177 caliber. For the Canadian market this gun was derated to less 500fps muzzle velocity. What I would like to know is if the muzzle velocity can be increased by sourcing a higher rate spring (if so where?) or machining a spring shim to increase the preload. Also, much the same question for a Beeman air rifle. If I have a Canadian market version with the lower muzzle velocity is there a means to increase it?

    Mr. Mike.

  2. #2
    Join Date
    Oct 2007
    Location
    Demokratik Republik of Washington
    Posts
    256

    Default Can't say for sure

    There are a few blogs around for airguns, even a few Canadian ones.

    From what I understand... some of the airguns are derated by drilling holes in the pressure tube and others by reducing the strength of the spring.

    I don't have my list of links here but there is a forum... Airgun Machinist Workshop... I think. You might ask over there.

  3. #3

    Default

    Quote Originally Posted by huntinguy
    There are a few blogs around for airguns, even a few Canadian ones.

    From what I understand... some of the airguns are derated by drilling holes in the pressure tube and others by reducing the strength of the spring.

    I don't have my list of links here but there is a forum... Airgun Machinist Workshop... I think. You might ask over there.
    Please try to find the link,Google search did not turn up any results.

  4. #4
    Join Date
    Jan 2009
    Location
    Southern WI
    Posts
    161

  5. #5
    Join Date
    Jun 2009
    Location
    Western NC
    Posts
    54

    Default Try this

    Google Chinese airgun forum, I was active in this forum years ago when hi
    power Chinese airguns hit the market. It was common practice to replace the
    stock spring with a Maccari spring, you can also find info on better seals.
    There are alot of tips on how to increase FPS for any brand of airgun.

  6. #6
    Join Date
    Oct 2007
    Location
    Demokratik Republik of Washington
    Posts
    256

  7. #7
    Join Date
    Nov 2006
    Location
    Louisiana
    Posts
    334

    Default

    Lot of good people and info at airgunone.com

  8. #8
    Join Date
    Jul 2003
    Location
    Southern Oregon
    Posts
    597

    Default velocity

    Hi
    When the piston comes to a stop the air has been compressed into a given space. If that space is reduced the pressure will go up and the velocity increased. Redesign the piston to accomplish this. A longer barrel will increase the performance also. With a precharged pneumatic the space after the regulator is increased to accomplish an increase in velocity.
    With the pneumatic using a longer barrel will tend to make it much quieter.
    Yankee1

  9. #9
    Join Date
    Feb 2007
    Posts
    379

    Default

    Try
    http://www.airgunforum.net
    and
    http://www.airgunbbs.com
    The forums there are a great source of information.
    Stronger spring, increased swept volume and reduced (if any) headspace will all increase power.
    If the trigger mechanism latches on a rod which extends from the piston head out the back of the spring then this is often lengthened to reduce power, if you have spare length & the spring & cocking mechanism will deal with it, shortening this is one way to increase swept volume.
    Barrel length is a funny one on a springer, on high end guns like the Beeman R1 shortening the barrel can increase power, on PCP & CO2 lengthening gives more up to a point,
    Regards,
    Nick
    Last edited by NickH; 07-25-2009 at 05:10 AM.

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