Shotgun: turning a fluted barrel to obtain a true cylinder

Discussion in 'Gunsmithing Forum' started by intmail01, Oct 24, 2016.

  1. intmail01

    intmail01 New Member

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    Hello,

    I have a Mossberg 500 shotgun and it was provided with a fluted barrel. I want to customize the barrel then turn it in lathe to remove metal from the takedown screw which maintain the magazine tube in direction to the chamber.

    Could sone tell me if there is a risks.

    The goal is to obtain a true cylinder from the takedown screw for about 18cm along the barrel.

    You can find many diagrams on google by entering key words "mossberg 500 diagram"

    Thank You
     
  2. JTJ

    JTJ Well-Known Member Supporter

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    By "fluted" do you mean rifled internally? Why do this when you can get a cylinder bore barrel for about $80?
     

  3. danf_fl

    danf_fl Retired Supporter

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    Welcome to the forum! Stop by "Introductions" and say "Hi"

    I googled "mossberg 500 diagram" and did not see any "fluted barrel"
    https://en.wikipedia.org/wiki/Fluting_(firearms)

    Please clarify if you are looking at lands and grooves inside the barrel (aka: rifling).
     
  4. c3shooter

    c3shooter Administrator Staff Member

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    Mety manana olana eo amin'ny basy nandika teny. Any Etazonia, ny fluted barika manana andalana sokitra ao amin'ny ivelan'ny barika. Moa azo eritreretina ve fa hoe ny hobaboina barika, miaraka amin'ny andalana Hetezo ny ao anatiny ny barika? Tsy miteny Malagasy, ary izaho mpandika teny mampiasa ordinatera fandaharana.
     
  5. KG7IL

    KG7IL Well-Known Member

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    I guess C3 answered it clearly
     
  6. c3shooter

    c3shooter Administrator Staff Member

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    KG- ny reninao tafika wers kiraro :p


    The man speaks my language much better than I speak his- and some words just do not translate worth a hoot.
     
  7. intmail01

    intmail01 New Member

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    Fluted barrel means large diamater at the chamber and gradually diminish to the muzzle. It is the external shape not the internal.

    Please dont translate your post in my native language, it becomes unreadable.
     
  8. danf_fl

    danf_fl Retired Supporter

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    My opinion?
    I would not do that.

    That part of the barrel is basically a "chamber" for the shells. That is the part that helps to contain the burning of gases in the shell. There is normally a reason that some parts are thicker than others, and reducing the outside diameter could create a weaker than normal area with some explosive results.

    As the load proceeds to the muzzle, the pressures reduce (allows for less metal at the muzzle area.

    http://www.mossberg.com/wp-content/uploads/2016/03/12173-Owners-Manual-Pumps-English_V.pdf
     
  9. primer1

    primer1 Well-Known Member Supporter

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    ^^^^^What he said, unless you want your barrel to look like this. The chamber is containing a small explosion, and weakening that wall could lead to little things like missing fingers, eyeballs, etc.

    [​IMG]
     
  10. c3shooter

    c3shooter Administrator Staff Member

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    Can you do it? Maybe.

    Going towards the chamber 18 cm from the takedown stud is not yet getting into the chamber area. However, much will depend on how much of the barrel material is cut away in the lathe turning. At a minimum, I would suggest that the barrel be proof tested after the machining.

    It would not be safe to assume that you could cut as deeply as the bottom of the flutes. The thicker material between flutes serves to reinforce the flutes, and you would be removing that.

    Fluted shotgun barrels are relatively scarce in the US, rifled barrels are common. We wanted to be sure we were speaking of the same thing. Sorry about the machine translation. Some languages it works (to some degree), others not as well. Your English is fine- some firearm terms just do not translate well. Glad to have you here.
     
  11. pavogrande

    pavogrande New Member

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    I did not comprehend the term either -
    to me fluting means longitudinal external grooves in the barrel -
    Tapered is big to small at muzzle -
    or did i miss something
     

    Attached Files:

  12. c3shooter

    c3shooter Administrator Staff Member

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    Pavo, the chamber and forcing cone area of the barrel are a larger diameter, and taper down to the standard bore size. Walls are thicker in that area, as pressures are greatest in that area.

    mossberg 500 barrel.jpg

    The area to be turned down would start at the mag tube lug, and go about 7 inches towards the chamber, which should avoid the heavier section. And yeah, barrel can taper AND be fluted at same time.
     
  13. pavogrande

    pavogrande New Member

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    Oh, I understand the physical characteristics of the barrel I just did not understand what he wanted to do --
    I see that the lug is pretty close to the muzzle so turning the barrel back seven inches would probably not be hazardous ---
    Not much taper at that point so probably would not remove more than about .015 to .020 in wall thickness at the max --
     
  14. SSGN_Doc

    SSGN_Doc Well-Known Member

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    Internal back boring, similar to a Vang Comp modification may be a bit more realistic to make the choke effect more gradual, and less likely to deform shot. This would not show a difference on the outer dimensions.
     
  15. Chainfire

    Chainfire Well-Known Member Supporter

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    C3, you need to stop drinking before 5:00. However, I do agree 100%.
     
  16. pavogrande

    pavogrande New Member

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    In another thread hearing loss was the topic --

    With my poor hearing that looks like what I think I hear -- :)