Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13
  1. #1

    Help me to identify this Upper....

    AR Flattop Upper, 16" 5.56 A2 Flash Hider...

    Markings on the barrel are as follows:

    B MP 5.56 NATO 1/9 H BAR

    I guess I can take some pix if needed.

  2. #2
    My BushMaster has the same markings, fwiw.

  3. #3
    Quote Originally Posted by JcJ View Post
    My BushMaster has the same markings, fwiw.
    Just trying to figure out who made the Upper. It has the same "keyhole" marking on the upper, but those were just the markings on the barrel. That would be awesome if it was a Bushmaster. I'd feel bad for the guy I traded though. He went from a Bushmaster 16" Upper, to a Model 1 Sales 11.5" Upper!

  4. #4
    Marksman r3126's Avatar
    Join Date
    Dec 2008
    Indy westside
    It is a Bushmaster. MP is for magnetic particle tested. Caliber, barrel and twist.

    There is a wealth of info here. AR15 / M16 FAQs

  5. #5
    Ok, checked over the site. Lots of good info. THANKS!

    Now I have two more questions....

    Magnetic Particle testing? I have no clue what it does, is for, how it improves the bore....

    HBAR.... WTF does HBAR mean? I thought it was just a heavy barrel, but I guess I'm wrong?

  6. #6
    Marksman r3126's Avatar
    Join Date
    Dec 2008
    Indy westside
    Without wanting to appear a smartass (which I sometimes am) use Google on your 'puter. There is a wealth of information available.

    From Wikipedia:

    Magnetic particle inspection processes are non-destructive methods for the detection of surface and sub-surface defects in ferrous materials. They make use of an externally applied magnetic field or electric current through the material, and the principle that the magnetic flux will leave the part at the area of the flaw.

  7. #7
    Certified Glock Nut shooter521's Avatar
    Join Date
    May 2008
    Indianapolis, IN US
    Quote Originally Posted by SavageEagle View Post
    HBAR.... WTF does HBAR mean? I thought it was just a heavy barrel, but I guess I'm wrong?
    No, you're right.

    The upper is Bushmaster; the "keyhole" marking indicates that the receiver forging originated at Cerro Forge.

    And now, for a bit of useless (or useful?) trivia:

    Forging marks/makers

    A (splintered) = Anchor Harvey Aluminum

    AF = Alcoa Forge

    C AF = Colt Alco Forge

    C MB = Colt / Mueller Brass

    Cardinal (stylized) = Cardinal Forge

    CH = Colt Harvey Aluminum

    CK = Colt / Kaiser Aluminum

    Circle/Crooshairs w/"AR" = ArmaLite

    CM = Colt / Martin Marietta

    D (stylized) = Diemaco

    DK = Diemaco / Kaiser Aluminum

    E = Emco

    EK = EMCO/Kaiser

    E MB = EMCO/Mueller Brass

    F keyhole = FNMI / Cerro Forge

    FA = FNMI / Anchor Harvey

    FK = FNMI / Kaiser Aluminum

    FM = FN/Martin Marietta

    FMB = FNMI / Mueller Brass

    Keyhole = Cerro Forge

    L = Lewis Machine & Tool

    LK = LAR / Kaiser Aluminum

    LM = LAR / Martin Marietta

    M (under diamond) = Mueller Industries

    PA = Capco / Anchor Harvey

    PM = Capco / Martin Marietta

  8. #8
    Well I'd seen some info on the process but not for the barrel. i didn't know if there was something different about how they do the barrel versus, say, a piston cylider or something.

    I'd looked it up, just too much info to sift through and none of it pertained to AR barrels. I just got a bunch of tech pages about **** above my pay grade! LOL

    Shooter, I appreciate your help. I know, I'm ignant. I've seen the keyhole stamp on just about every upper I've held besides the Colt uppers. Figured maybe it was just a normal thing!

  9. #9
    If you take off your handguard it will sometimes have stamped or rollmarked the manufactor...might be the upper, might be the barrel though.

  10. #10
    Join Date
    Apr 2008
    NW IN
    I'd rather have the Model 1 11.5" than the 16" Bushmaster FWIW- especially if 1/7.

Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts