Hammerli mods

Discussion in 'General Airgun Chat' started by JonH, Sep 14, 2015.

  1. JonH

    JonH Airgun Custom Designs

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    Hi Guys
    I think the AR20 is fairly straightforward gun to mod..

    I've done the usual: milled the shroud off, polished the body, cleaned/polished the internals, replaced the grip set to wood, off set the grip and trigger and added a butt hook.

    Has any one done anything to or replaced the nasty plastic rear stock?? Looking for some ideas :D

    cheers

    Jon
     
  2. Abdiel

    Abdiel Member

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  3. biggeorge

    biggeorge Member

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    Hello fellas.
    I'm pruddas.finest on the bbs.
    Here a link to some reviews people including me have done.
    http://www.airgunbbs.com/showthread.php?716964-My-little-review-on-the-hammerli-ar20ft

    I didn't replace the whole back stock but got a new custom made cheek adjuster from a one called Norris. Still got it somewhere.
    There was someone on tinterweb who has made an ali rear stock.
    Can't remember who tho! The old neurons aren't firing like they used to!
     
  4. JonH

    JonH Airgun Custom Designs

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    Thanks for this guy's. I'll take a lol at the threads suggested.

    I did think about an aluminium rear stock but worried adding further weight to an already heavy rifle. :confused:
     
  5. JonH

    JonH Airgun Custom Designs

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    I meant to say take a look not take a lol...lol:D
     
  6. JonH

    JonH Airgun Custom Designs

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    Love your set up biggeorge! :D
     
  7. Peter M

    Peter M Cantankerous primate

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    Whilst this threads active is there anyone that can be recommended for servicing a AR20FT? Preferably in the north east. I think mine has dropped power for no particular reason. I'm going to check it down the range this week but according to my end of barrel chrono its only putting out 8.5ftlb. Turned the power adjuster and its now 9.5ftlb, I'm hoping its my crappy chrono not reading properly to be honest but just thought Id put this up for now. Doesn't seem to be leaking and I've changed the bolt o ring just incase it was that.

    Just had a lovely hydro dip on my Hammerli but been technologically stupid I cant put photos up :D
     
  8. JonH

    JonH Airgun Custom Designs

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    Hi Peter.
    I bought mine from new and I had a sudden drop in power. I sent it back and they adjusted the grub screw above the reg and that seemed to have sorted it and I'm sitting with 10fps variation over the chrono.

    Have you recently cleaned and lubed the internals ? I made the mistake of putting grease on my hammer and hammer spring and as the gun got colder the pressure dropped as the viscosity increased. I know a stupid thing to do but happy to share my mistakes.

    It would be great to see your dipped hammerli. I 've attached a pic of mine :D

    Cheers Jon
     

    Attached Files:

  9. Altx

    Altx Member

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    Hi, just jumping in. other than making a hamster I have done nothing to mine..but I have been thinking about milling off the shroud. Does it really make a difference ?
    2 reasons being weight (got big Nikko on ) and if I was to do it I am sure it would enable me to take some weight off the back too, combined with a junior tube could be beneficial for those pesky standers. Also I get shift in the cold and think it is a bi metallic issue with different contractions if barrel/shroud?
    Anyone done it ? Is it recommended ?
    Thanks in advance.
     
  10. Lofty

    Lofty Member

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    Hi,
    Had mine milled off but not for weight issues , in fact as the frame / shroud is aluminum I don't think that there would be much of a saving. Did mine so I could fit a UK Neil air stripper to it. Then just got some carbon wrap from the bay to cover the now bare barrel.
    Some people did report on POI shift and IIRC there were 2 school's of thought about thie remedy for this ....
    1). Remove the 'O' ring from the end of the barrel that keeps the barrel central to the shroud.
    2). Mill the shroud completely.

    Both options allow the barrel to free float and I suppose milling the shroud removes any chance of the barrel touching the internal surface of the shroud if just the 'O' ring is removed.

    HTH

    Lofty
     
  11. JonH

    JonH Airgun Custom Designs

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    I didn't have any POI shift but I removed it purely for cosmetic purposes. I did it with bench drill, hack saw and a file. It's quite straightforward if you're fairly handy. I didn't notice any weight saving although changing the air tube I've heard will make difference apparently.
     
  12. Altx

    Altx Member

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    Ok makes sense. Food for thought . I shall have to make some space on the bench, appreciate the info..
    The price of the tubes is reasonable from Germany at the moment with exchange, mmm shiny
     
  13. Lofty

    Lofty Member

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    A point to bear in mind ref filling the AR's . I have heard that if they are filled to the max 300 bar (Assuming original cylinder OR the 300 bar Ali one) then the reg CAN lock up , apparently this has happened on occasion ?. Advice given is to fill to 200 bar max this will still give a good shot count.

    Cheers,
    Lofty.
     
  14. Peter M

    Peter M Cantankerous primate

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    When I bought mine it had an alloy cylinder fitted and personally I think taking the balance back over helps tremendously compared to other Hammerlis I have tried.
     
  15. JonH

    JonH Airgun Custom Designs

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    is it true the reg isnt from the Walther dominator? I've only read that from Walther owners though.....:)
     
  16. Lofty

    Lofty Member

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    Not sure , but it is a twin reg set up.

    Lofty.
     
  17. Akita

    Akita Member

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    Low readings with a combro can be a sign the combro needs its batterys replacing, on ebay there really cheap.

    "is it true the reg isnt from the Walther dominator? I've only read that from Walther owners though..."

    JonH the reg isnt from the fully fledged walther Dommie but the more budget 1250 dominator but the AR20 has two of them inline stacked together a high pressure and low pressure being on the firing side.
     
    Last edited: Sep 17, 2015
  18. Peter M

    Peter M Cantankerous primate

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    Bit more than that I think as the groups have went from a hole to a bunch of holes :eek:o
     
  19. shakeysimon

    shakeysimon Member

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    As there's already a thread on the ar20 I'm going to look at one at the weekend,is there anything in particular to look for,it's a very good price but still don't potentially want to buy a duffer,I'm hoping it turns out to be a genuine rifle
     
  20. mike

    mike Member

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    No! the reg is not from the 1250 Dominator, although the valve (larger part of the two stage reg) body is exactly the same the exhaust valve stem is larger in diameter and the exit hole is also larger, plus also the exhaust valve spring is shorter and has a softer spring rate, and the bevillelle washer's are stacked in a different order.

    You can if you wish run the AR20 of just the larger reg by removing the smaller first stage part, this is only used to reduce the air pressure from 300bar down to 200bar (remember what these rifle's were designed for, indoor comp's 300 bar = 400 shots) You can then only fill to 200bar but this will still give you 80 - 100 shots depending on the size of you air cylinder.

    Care must be taken when taking apart the reg's as all the threads are locked tight with an extremely good locking compound that can required some heat, to much heat will melt the pollyurathain seals and the sizes are a bugger to get hold of.

    As to servicing a AR20, there's not a lot to do and it's a very simple rifle to work on, and if anyone tell's you that they are made of monkey metal what a load of bull! The Ally shroud and breach are made from top quality Ally, just pick up the breach on its own and feel the weight or ask the Guy who milled my shroud for me. (Phone No supplied) even the weights in the stock are all Ally.

    I have read elsewhere that someone suggest that the sears on the trigger would wear out due to the parts being cheaply made, again bulls@#t. My AR20 is over three years old and has been used for HFT almost every weekend, so it's had several thousand's of pellets through it and there are no signs of any wear on the sear's nor have any of the seal's failed.

    The only faulty part is the design of the reg and they tend to only last about 3yrs before the start to lose pressure. A new one can be had for about €95 from Gremany or I have heard that you can get them for £66 exchanged but the UK importer won't have any until the new year.

    ATB
    Mike
     

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