Air escaping from breech of LG110

Discussion in 'Steyr' started by NoMarkLeft, Oct 11, 2015.

  1. NoMarkLeft

    NoMarkLeft I can spell virgin now

    Joined:
    Mar 24, 2010
    Messages:
    21
    Location:
    Aylesburg
    After some strange results with pellets going high and low when they shouldn't. I went through the usual cleaning barrel ,check pellets , Chrono showed down a little on output with a handful of high and low fps between some of the 40 shot string. Turned the output up slightly ,seemed quite settled over the chrono now. Zeroed yesterday and seemed to be shooting okay then tried the tissue paper test on the breech that someone suggested and it definitely has air escaping .
    Could this be the issue all along ?
    Any advice would be appreciated.
    Thanks
    Mark.
     
  2. Ratinator

    Ratinator Well-Known Member

    Joined:
    Jan 2, 2010
    Messages:
    2,568
    Location:
    stourport
    Club:
    Millride FTC / Nomads
    Where is the leak

    On top of the piece that travels forwards to close the breech is a small black sear, that looses air when activating the stabaliser . If the air is coming from the under side of that piece you need a thin washer under the transfer port, you can buy them or make one from film negative.
    Loosing air from the port will give inconsistency , you might benefit from a new seal on the top of the port also.
     
  3. NoMarkLeft

    NoMarkLeft I can spell virgin now

    Joined:
    Mar 24, 2010
    Messages:
    21
    Location:
    Aylesburg
    Okay, so the air escaping from the piece that travels forward closing the breech is normal ?
    I placed some small tissue pieces either side of this at the bottom and air is coming from the transfer port area.
    Can you remove the 0 ring and just replace this or do I need the complete transfer port with 0 ring ?
     
  4. Ratinator

    Ratinator Well-Known Member

    Joined:
    Jan 2, 2010
    Messages:
    2,568
    Location:
    stourport
    Club:
    Millride FTC / Nomads
    Yes

    Yes you can just remove the o ring , I've changed mine.
    There may be a number of reasons you are loosing air there, thin washer , faulty o ring or maybe your barrel needs to go forwards a smidge.
    The bottom is tapered so if the barrel goes forward you will reduce the gap between the two.
     
  5. NoMarkLeft

    NoMarkLeft I can spell virgin now

    Joined:
    Mar 24, 2010
    Messages:
    21
    Location:
    Aylesburg
    Thanks for your help and advice .
    If I needed to replace the 0 rings , where would I be able to source them from?
    I have seen them advertised on the Bay, though these are not original ones.

    Thanks
    Mark.
     
  6. Ratinator

    Ratinator Well-Known Member

    Joined:
    Jan 2, 2010
    Messages:
    2,568
    Location:
    stourport
    Club:
    Millride FTC / Nomads
    Flip it

    The o rings bought individually on the bay are fine, you may be able to just flip it over.
    I would try the washer first then the o ring and then the barrel. If you move the barrel make sure you have some forward travel in the trigger block.
     
  7. Sundance

    Sundance Member

    Joined:
    Mar 10, 2013
    Messages:
    274
    Location:
    swansea
    side grub screw

    Just to butt in...I don't want to teach Granny to suck eggs and forgive me if I'm assuming you might not know but if you have been altering the the velocity via the rear adjuster then don't forget that before you move this you need to loosen off the grub screw at the side of the action and tighten again when you are happy with the fps..

    otherwise you might find another source of output variation...
     
  8. NoMarkLeft

    NoMarkLeft I can spell virgin now

    Joined:
    Mar 24, 2010
    Messages:
    21
    Location:
    Aylesburg
    Thanks mate , I did know this. Though appreciate your input:):cool:
     
  9. hmangphilly

    hmangphilly Not quite a full phil

    Joined:
    Nov 5, 2013
    Messages:
    1,906
    Location:
    wimborne
    Don't forget there's an oring inside that sliding 'bolt' that seals against the end of the barrel
     
  10. NoMarkLeft

    NoMarkLeft I can spell virgin now

    Joined:
    Mar 24, 2010
    Messages:
    21
    Location:
    Aylesburg
    Clocked that, How the heck do you remove that one?
     
  11. hmangphilly

    hmangphilly Not quite a full phil

    Joined:
    Nov 5, 2013
    Messages:
    1,906
    Location:
    wimborne
    Needle or hooky pick .
    It's a whacky size . Give us a shout if you struggle
     
  12. chrisc

    chrisc Lucky git

    Joined:
    Apr 17, 2009
    Messages:
    2,666
    Location:
    Barnsley
    Hi Mark, some good answers there from some knowledgeable chaps.:)

    To replace the transfer port and breech seal is a doddle. A strong needle will suffice.

    transfer port is - item 12 O-ring 6x2 Steyr part no 3301020026
    breech seal is - item 53 O-ring 5.28x1.78 Steyr part no 6390050

    As has been said, air from the top of the breech where the stabiliser 'flipper' is normal but air blowing at the bottom of the breech is not so good. You'll be using too much air per shot, winding up the hammer spring to get the power to a normal level and that upsets the whole balance of the rifle. Reg pressure vs firing valve spring tension vs Hammer spring tension are important for that dead feel and IMHO also makes for tighter long range grouping.....no real science behind it, just what i've observed over the years.:eek:

    If you replace both o rings and make sure you have a positive 'lock' when closing the cocking lever (which might need the barrel to be moved to achieve) and you're still loosing air under the breech then you might need a very thin shim under the transfer port, although finding a shim fitted is actually quite rare. Getting a positive lock on the cocking lever can sometimes be tricky as if it's it's too tight then the lever can suffer excess wear and premature failure where it starts to grab.
     
  13. NoMarkLeft

    NoMarkLeft I can spell virgin now

    Joined:
    Mar 24, 2010
    Messages:
    21
    Location:
    Aylesburg
    Many thanks to all the advice given.
    I flipped over the transfer port 0 ring and there was still a bit of air escaping from one side??
    So replaced with a new 0 ring and all seems good !
    Will run over the Chrono later to check the fps and adjust if required. One more question though what sort of fps
    is the Steyr happy running 8.4 pellets at?
    Once again I am very grateful for the help from you folks
    Cheers
    Mark:):):):):):):):):):):)
     
  14. chrisc

    chrisc Lucky git

    Joined:
    Apr 17, 2009
    Messages:
    2,666
    Location:
    Barnsley
    Mark, Both my Steyrs shoot sweet at 775-780 fps. I've tried running them as close to the limit as possible but it's just not worth the risk of tripping over if the temp goes up and it makes sod all difference with the extra 20fps anyway.:)

    Gald you got sorted.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice