WWII RAF Gun Harmonisation

Discussion in 'Aviation' started by Greyman, May 25, 2014.

  1. Greyman

    Greyman Active Member

    Joined:
    Jan 31, 2009
    Messages:
    711
    Likes Received:
    130
    Trophy Points:
    43
    • Like Like x 1
  2. pinsog

    pinsog Member

    Joined:
    Jan 20, 2008
    Messages:
    658
    Likes Received:
    15
    Trophy Points:
    18
    #2 pinsog, May 25, 2014
    Last edited: May 25, 2014
    Nice beginning. What is the size are the target rings in your example?
     
  3. Greyman

    Greyman Active Member

    Joined:
    Jan 31, 2009
    Messages:
    711
    Likes Received:
    130
    Trophy Points:
    43
    On the 'Bullet Group' page there is no size, it's just a representation of a typical group. The size varies depending on what aircraft and in which mounting the gun is located.

    On the 'Harmonisation Pattern' page the first three groups of images are typical groups from an eight-gun Spitfire (I or II). They're not from specific tests but are for illustrative purposes. These are a little larger than 1/3 of a degree (75% zones).

    In the fourth group of images (typical groups from a Spitfire Vc), the darker groups are from the cannons, and are slightly smaller than 1/3 of a degree (75% zones).
     
  4. bobbysocks

    bobbysocks Well-Known Member

    Joined:
    Feb 28, 2010
    Messages:
    3,809
    Likes Received:
    181
    Trophy Points:
    63
    Location:
    Pennsylvania
    how was the 303 browning mounted and was it shot in short bursts or did they run the belt? even at 50 yards if mounted on a tripod and shot in bursts by a trained gunner ....the group should have been tighter.
     
  5. Greyman

    Greyman Active Member

    Joined:
    Jan 31, 2009
    Messages:
    711
    Likes Received:
    130
    Trophy Points:
    43
    I don't have specific figures for the Spitfire as of yet, but 1/3 of a degree is typical of a wing-mounted gun, and I'm sure is close to the average group from a Spitfire.
     
  6. Shortround6

    Shortround6 Well-Known Member

    Joined:
    Jun 29, 2009
    Messages:
    9,769
    Likes Received:
    800
    Trophy Points:
    113
    Occupation:
    retired Firefighter
    Location:
    Central Florida Highlands
    There are a number of things that can affect the grouping of a Browning machine gun. The guns can certainly be set up to shoot better if that is what is wanted. The "cooling" jacket is also the support for the forward barrel bushing and the tightness of this bushing affects things as does the headspace adjustment and buffer.
    With the emphasis being place on shotgun like (or worse) patterns perhaps the 1/3 minute zone was a deliberate set up of the gun itself.

    I would note that the RAF was not alone in this pattern thinking as the quad .5 Vickers naval mounting had each gun pointed in a slightly different direction which certainly increased the chances of getting a hit even if if it didn't do much for actually shooting down a plane that needed multiple hits.
     
Loading...

Share This Page