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Thread: Lack of barrel crown?

  1. #1
    Join Date
    Dec 2012
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    Bristol
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    1,116

    Lack of barrel crown?

    Hello, sorry if this is a silly question but I have a CO2 pistol which at 10 yards the point of impact is 6" high and 4" left. The sights are non adjustable. Having just looked at the barrel I find that there is no crown at all.
    This is the only pistol that I have which is crownless.
    Problem is that the barrel is part of the valve assembly and can't be separated.
    It's a .177. Any ideas chaps. A countersink with a long .177 nose perhaps. If I could separate the barrel then I could put it into the lathe BUT -------------------------------.
    Thank you for any ideas, thoughts etc.
    Cheers.
    Geoff.

  2. #2
    Join Date
    Dec 2016
    Location
    leeds
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    2,059
    you could try using a allen bolt with a ballbearing epoxied in the head
    a little valve grinding paste and a drill go steady in forwards and reverse to avoid a folded edge forming on one side of the grooves

  3. #3
    Join Date
    Dec 2012
    Location
    Bristol
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    Thank you Ped, I have everything apart from the 'balls' ,am going shopping today and will give it a try later.
    Cheers.
    Geoff.

  4. #4
    Join Date
    Mar 2001
    Location
    near rotterdam,netherlands
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    3,536
    Dont think barrel crown has anything to do with POI. Only with (lack of) grouping/accuracy.
    What pistol are we talking about anyway?
    If it has grooves and lands, it has a crown too, no doubt. But sometimes, its recessed and not easily visible
    Post a pic if you can.
    ATB,
    yana

  5. #5
    Join Date
    Aug 2010
    Location
    Worthing
    Posts
    698
    I have a CP1 that wasn't crowned at the factory, so it had a thin protruding lip from where the rifling had been formed. Shot all over the place. I used a dremel and grinding stone to give it a crown. Seems to work fine now. Brownells do a superb range of tools, but the 45 degree crown cutter with central bore guide costs £125. They also do some nice brass lapping tools for £12 or so.

  6. #6
    Join Date
    Dec 2012
    Location
    Bristol
    Posts
    1,116
    Hello, well the pistol is a Daisy, OK I know ------------- space for laughter -------------. It has a rifled barrel but there is no crown just a square cut end which is a little rough, looks like a 'machining' action which was not finished. At 30 feet then about a 4" group but it was difficult because it was very cold and I was loosing feeling.
    The group as such was high and left, such that I had to aim off target to hit it.
    Am I exscpecting too much? I don't have many pistols Crosman 600's and a 357. Lots of rifles though.
    Thanks chaps.
    Cheers.
    Geoff.

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