Custom Tuned RAW .22 Poly

Forums PCP Airguns Custom Tuned RAW .22 Poly

  • Views : 656
  • Link

    terrymc
    Participant
    Member

    Hi Guys and gals,

    Some of you that frequent the RAW Report have seen where I have a RAW .22 polygonal barreled rifle with a laminate sporter stock.

    The story behind this is I bought it off of another shooter that had too many projects and this had some issues that needed to be resolved.
    We talked, came to a price, and I bought it with the full intent to have someone that I know and trust work on this rifle.
    This “project gun” arrived I did a little testing and found it definitely was not shooting up to snuff.
    The accuracy was there but the shot count and the extreme spread were not any where near where they can be.

    Here is the graph of what I found.
    All shot are JSB 18.1 gr 
    I shortened it to a range of 200 bar down to 120 bar since outside of that range it was even worse showing a 65fps E.S.
    Within the 200-120 range is still has an E.S. of 36 fps!
    Std. Dev. was 8.70.
    And it only got 69 shots at 32.6 ft. lbs.
    Additionally it can be seen that the FPS just continues to fall down from the first shot to the last in a downward slope.

    So I take to the person I know and trust to work on RAW’s, Mark Buchanan.
    Mark has already worked on one of my other problem children (my .30 LRT) and worked his magic on it.
    I know a lot of people have received a lot of help from Mark over the years and he provided some very useful information on this forum.
    I don’t want to get into a what happened to Mark and Martin discussion as that is between them.
    I will just leave it at Mark knows these rifles and his work shows it.

    I dropped the 22 off to Mark and we had a discussion of what I had been told by the previous owner and what I saw on the chrono results.
    I know that his work is very comprehensive and that is is not a simple turn the hammer spring this much and adjust the regulator to this point.
    I discussed Marks work with several members on here before taking him my first rifle to him and they all said that it is “transformed” to quote one individual.
    Being a skeptic I like to judge results.

    So here is the first post MB tune graph. 
    This one is for a direct comparison between 200 bar and 120 bar.
    Keep in mind this one is on a different scale so differences are exaggerated.
    Pellets are 18.1 gr JSB unsorted or weighed.

    So what does this graph tell me.
    Well to start with I now get 83 shots for the same fill instead of 69.
    Then I go into the fact that this happens at 35.0 ft. lbs instead of 32.6
    Then we get  into more details like what you are seeing there is only 8 fps Extreme Spread instead of 36 fps.
    In fact the E.S. is less than the std. dev. of the pre-tune state.
    What did we wind up with for std dev.? how about 1.78 fps.

    NICE BUT WHAT ABOUT A FULL FILL?
    ​Pellets are 18.1 gr JSB unsorted or weighed.

    Well what can I say.
    119 shots at 34.6 ft lbs average!
    The regulator sweet spot is happiest between 200 and 120 where it gets 8 fps E.S. but fill it up to 230 bar and we still get 13 fps E.S.
    Std. Dev. of 3.0 fps.

    As far as accuracy, the gun and barrel were already excellent, and these changes just made the accuracy that much better.
    With the right shooter this could easily be an EBR 25 meter winner.
    All I can say is Thank you Mark!
    The results speak for themselves.

     

    Link

    Imold
    Participant
    Member

    Very nice terrymc very nice…

    Link

    terrymc
    Participant
    Member

    I forgot to mention some of the other things that come with the tune.
    Since the gun is shooting more efficiently, there is a lower report.
    Both my 30 and my 22 are quieter now that they have been tuned.
    Another unexpected thing is lowered cocking weight due to a lower hammer spring preload.
    by being lighter the cocking lever is smoother in action, not that it needs it. 

    Link

    FredSG
    Participant
    Member

    Terrymc,

    I’m curious.  Why wasn’t the .22 RAW returned to martin for a tune up before selling it to you for the great work that was done by Mark?  I would think Martin would have been able to correct the shooting issues for the original owner . . . just wondering?

    FredSG

    Link

    terrymc
    Participant
    Member

    The previous owner works on his guns himself.
    He intended to do the work and had too many other guns that he is working on so he decided to sell this one.
    He has a large collection of high dollar guns.

    Link

    Glem.Chally
    Participant
    Member

    That’s amazing Terry,  must be super happy to see that back.  Great work Mark!

    Link

    terrymc
    Participant
    Member

    Hi Glem,
    yeah I am very pleased.

    Mark does very good work.
     

    Link

    terrymc
    Participant
    Member

    So as I was shooting tonight, I was marveling at how light he cocking is on this tuned 22.
    It was light and smooth before, but I cock this with one finger now.
    It got me to wondering what is the cocking weight.
    So I grabbed my trusty Lyman trigger gauge and measured it.
    Not bad, it did 6 lbs time after time +-1 oz.

    One of the things I changed this past weekend is the area around the trigger guard for the sporter stock.
    It hits me in all the wrong places so I got out my dremel and some sand paper as well as a round wood rasp and went to work.
    Big difference.
    Before

    After, notice the ridge around the trigger well is now gone and the ridge that runs back to the grip area is gone as well.

Viewing 8 posts - 1 through 8 (of 8 total)

You must be logged in to reply to this topic.