MPR Trigger adjustment

Discussion in 'Air Arms' started by Stoohundred, Nov 9, 2015.

  1. Stoohundred

    Stoohundred New Member

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    Hi, the trigger on my MPR is still set as it was from the factory and is a little heavier than I would like it to be, as I am using it for FT, could anyone give me any tips on which screws to adjust to lighten it a little without having to change or cut any springs.

    As far as I know there's one screw by the trigger guard which is the weight of pull? And the two on the trigger are the 1st and second stage.

    I like the feel of the stages as they are, I would just like the second stage lighter, so should I adjust the weight of pull screw or the second stage.

    There is a fantastic guide on adjusting the s200 trigger by "timminder" I think,

    Is there anything else on here for the s400/MPR?
     
  2. poth

    poth Whafta old Gits world champion

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    Just take the side plate off and you can see what is happening that's the easiest way to do it
     
  3. Stoohundred

    Stoohundred New Member

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    Cheers

    Yeah, cheers for that, About as much use as a chocolate teapot!
     
  4. eyewitnesss

    eyewitnesss Government Spy

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  5. mikeygasbag

    mikeygasbag Member

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    That's not really the sort of reply that will get people falling over each other to help you, and only your second post too.

    What Ken (Poth) suggested IS the best way to adjust any of the Air Arms trigger units, and it's the method that I always use. The benefit is that you can see the exact effect that any adjustment has on the way the trigger sears engage with each other.

    There are a few small modifications that can be done to make the trigger action smoother and the release a little lighter and more consistent. Do a quick search on the Air Arms Owners Club forum. There are some very good trigger tuning guides on there.

    Just out of interest, the trigger on my HFT 500 was horrendous straight out of the box, it was very heavy and had an inconsistent release. After identifying a small burr on the bottom of the third sear where it engages the top of the second sear, I polished the burr out and the trigger is now acceptable.

    Good luck with it.

    Mike.
     
    Last edited: Nov 10, 2015
  6. DEAN C.

    DEAN C. Steyr Convert

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    The only way to set them up properly in my opinion is to take the side plate off, just like Poth has said.;)

    There is a very good guide on the Air Arms owners forum that has pictures, with the side plate off :)

    I have set my 2x 400's and 2x MPR's and 410 up many times to get them how I like them and I still cannot do it properly without seeing inside, even though I know what screw does what. It is much easier because when you alter one setting you are also altering the other settings, that is why you need to see what is happening inside as you adjust. I will guarantee you will mess it up first time if you try and adjust it without, and the sears will not engage properly, or even be dangerously set. I have had an accidental discharge into the floor(from my MPR not me) at a shoot without touching the trigger, and its not nice, safe, and certainly very embarrassing.

    Its not as bad as it sounds and certainly worth spending time on the 400/500 series triggers, they can be quite acceptable when set, polished and shimmed.

    PS Just seen Mikeys post above and he's said more or less the same as me regarding AAOC guide etc. Sorry for repeating.:eek::D
     
    Last edited: Nov 10, 2015
  7. Tench

    Tench WHFTA World Champion 2016.

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    Yes the best way to understand the effect off adjusting any of the screws is to take the side plate off, and once you have done this it is the advice you would give to others asking the same question.
    So don't be Stoopid, listen to the advice as that is what you asked for!
     
  8. poth

    poth Whafta old Gits world champion

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    Next time you ask for help it won't be from me
     
  9. MickyFinn

    MickyFinn I❤HFT

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    Or me! Figure it out yourself:eek:o
     
  10. stryder5

    stryder5 New Member

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    Come on guys, he's new to the forum and its etiquette , so let's give him some leeway.

    If you are new to rifles and not an engineer it could be difficult to understand what's going on even if you see it with the side plate removed.

    The answer to the original op question is you adjust the second stage, which way to turn the screw depends on how the sears are arranged, but clockwise generally makes the second stage lighter.
     
  11. killen

    killen Senior Member

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    I have recently struggled with the MPR trigger and in fact the air arms manual is of little help. It only identifies which screw does what.
    After loads of wasted time, here is what I think is an idiot proof way of setting them up.
    First remove the side plate as the guys say.
    Next ensure the weight of pull spring is not too slack. Its best to have this a little strong for initial setting up the trigger. Next back off (screw out) the second stage screw until it is well away from making contact with the bottom sear.
    Next play around with the first stage screw until it just won't cause the rifle to fire. This is by screwing it out. This is easy to achieve as initially it will fire the action every time. When it won't, the trigger is in the position it should be i.e. on the edge of the sear. Next adjust the second stage screw until it starts to make contact with the bottom sear, by screwing it in. Its set when it just causes the rifle to fire.
    Basically the first stage screw takes the sear to the edge and with a little more travel of the trigger, the second stage screw just pushes it over.

    Just check now that its not too light. If it is back off the first stage a fraction. It's this tiny amount of setting the first stage that gives the trigger its correct or incorrect feel.
    Finally set the spring force to give you what you want heavy or light.
    If non of this works, buy some new sears and make sure there are copper washers either side of each sear. Also don't put heavy grease anywhere.
    Hope that helps.
    PS non of this works for an EV2 they are a mystery to me :eek:o
     
  12. Stoohundred

    Stoohundred New Member

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    http://http://www.shootforum.com/forum/s4x0trigger.html

    Got this guide from Geordie over on the aaoc, just what I was looking for, And thanks for the replys on here too chaps, and to the guys who pm me too.

    Have sorted my trigger lovely now using the guide above, and it's awesome, much better follow through and no "pulled" shots,

    I highly recommend the trick with a small nail/panel pin that limits the length of pull after trigger release .

    Also please note, all newer s400/ MPR series will have a 3 sear set up, but the set up instructions all work just the same.

    Thanks again chaps.
     
  13. mikeygasbag

    mikeygasbag Member

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