Page 1 of 2 12 LastLast
Results 1 to 15 of 19

Thread: BSA Airsporter - Stuck piston

  1. #1
    Marksman

    User Info Menu

    Default BSA Airsporter - Stuck piston

    Hi All,

    I got my hands an Airsporter(MK7) that would not cock. I disassembled the rifle, and now I cannot get that piston out. I soaked it overnight with Q 20, tried again, and it would not budge.
    I jumped on it with all my weight, but it keeps on laughing in my face.

    What other methods can I try?
    Sign Up To Air Rifle SA Forums

  2. #2
    Inactive Member

    User Info Menu

    Default

    Hello,

    You could try heating the outside of the compression tube with a hair dryer or heat gun.....

    Cheers.
    Sign Up To Air Rifle SA Forums

  3. #3
    REP: Air Rifle Services

    User Info Menu

    Default

    I had the same problem a while back. The o-ring is the wrong size. I resorted to gently heating the tube with a hot airgun and pounding the piston out using a steel rod down the barrel you will have to repeat the process a number of times. Once you have the piston out you'll need to polish the compression chamber to get the residue gunk out. Good luck
    Sign Up To Air Rifle SA Forums

  4. #4
    Marksman

    User Info Menu

    Default

    Thank you for your advise. I got the piston out with some heat from the wife's hear dryer.
    I made contact with Vrystaat for some spares, so will hopefully get her shooting soon.
    Sign Up To Air Rifle SA Forums

  5. #5
    Sharp Shooter

    User Info Menu

    Default

    Quote Originally Posted by Njappers View Post
    Thank you for your advise. I got the piston out with some heat from the wife's hear dryer.
    I made contact with Vrystaat for some spares, so will hopefully get her shooting soon.

    And? Sorted?
    Sign Up To Air Rifle SA Forums

  6. #6
    Marksman

    User Info Menu

    Default

    I got the rifle shooting again after making my own buffer washer and tap shim. Sourced tap spring from an old lighter.
    The rifle is not shooting well though. It shoots 5 to 7cm low at 10m. I think it needs a main spring replacement. I screwed the cylinder and trigger housing in by hand without difficulty.
    The tap lever is broken, and the tap shim I made will not last. I need these parts, but Adriaan is not getting back to me.

    Who else will be able to help with parts?

    Thanks,
    Njaps
    Sign Up To Air Rifle SA Forums

  7. #7
    Marksman

    User Info Menu

    Default

    I got this rifle shooting nicely. Good tight groups at 10m. Replaced the spring with a shortened universal spring. Took a couple of attempts before it felt right. It still vibrates quite a lot though. I am sure it will run in with time.

    On another point...I was fortunate to get my hands on a .22 Airsporter in great condition. It had a broken spring. I bought another universal spring, but this one had a thicker wire than the other and the original. It fitted in the piston so I gave it a go like before. The problem I have now is that I cut 10 coils off already, and she still kicks like a mule. Very difficult to cock too. How short can I really go? I tried to find a spring with the original springs specks, but no luck.

    Should I forget about mending other springs to fit, or is there a place in Pretoria with a better selection of springs to choose from?

    Regards,
    Njaps
    Sign Up To Air Rifle SA Forums

  8. #8
    Inactive Member

    User Info Menu

    Default

    Good evening...I have an old tect document that mentions spring sizes and coils.
    What it says for Airsporter is the following:
    OD 20mm
    ID 15mm
    coil thickness 3mm
    lentgh 270mm
    coils 29 - 32

    Hope this helps
    Sign Up To Air Rifle SA Forums

  9. #9

  10. #10
    Inactive Member

    User Info Menu

    Default

    My recommendation. Get a spring close to the specs of the original spring. Fit it and test fire it - OVER A CHRONOGRAPH. Cut and dress the spring until you get close to the original foot-pounds/velocity of the rifle. This is how I go about it.
    Sign Up To Air Rifle SA Forums

  11. #11
    REP: WS Airguns

    User Info Menu

    Default

    I have found it works better for me to collapse coils to reduce "kick" than cutting more coils off the total lentgh. A shorter spring is not always a bit weaker....
    Sign Up To Air Rifle SA Forums

  12. #12
    Sharp Shooter

    User Info Menu

    Default

    Quote Originally Posted by wimpie swart View Post
    I have found it works better for me to collapse coils to reduce "kick" than cutting more coils off the total lentgh. A shorter spring is not always a bit weaker....
    Agreed.
    Butane torch, pair of leather gloves and a hard flat surface. Heat 1st two coils to red hot and push against flat surface, maintaining straightness. Some to other end if fps is still too high.
    If both ends done and fps still too hi, then angle grind collapsed end flush and repeat the collapsing part.
    Eventually you get what you need and the collapsed ends absorb a lot of twang.
    Sign Up To Air Rifle SA Forums

  13. #13
    Marksman

    User Info Menu

    Default

    Thank you for the advice. I grinded and polished the cut end until smooth. I then scragged the spring for 6 hours. The cocking and shooting cycle is really nice after re-assembly. I have no idea what speeds I am shooting at, and it groups badly. I have only tried one type of pellet, so maybe it is just pellet fussy like my other Airsporter. I will have to borrow a chrony and take it from there.
    Sign Up To Air Rifle SA Forums

  14. #14
    Sharp Shooter
    Forum Sponsor

    User Info Menu

    Default

    I had a Airsporter MK7 that was difficult to cock and kicked like a mule even though it was only shooting at 620fps met JSb 8.44's. It was heavily over sprung with a lot of pre-load so I removed 7 coils from the spring. After that I could assemble the rifle without a spring compressor, the cocking cycle was much nicer and the rifle was actually very pleasant to shoot. The average speed went up slightly to 630fps. They can produce a bit more power but it was shooting so nicely that I decided to leave it as is and shoot it with open sights.
    Sign Up To Air Rifle SA Forums

  15. #15
    REP: WS Airguns

    User Info Menu

    Default

    And tonight I will be starting to work on an Airsporter with seal end of piston stuck in tube, spring and pistonbody apperantly out of tube.
    Fun times....
    Sign Up To Air Rifle SA Forums


Similar Threads

  1. BSA Airsporter
    By Pietsweis in forum Vintage | Antique | Collectable Airguns
    Replies: 21
    Last Post: 09-04-14, 14:23

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Friends of Air Rifle SA