RAF GM2 MKII Reflector Gunsight

Discussion in 'Other Mechanical Systems Tech.' started by Flea, Apr 7, 2011.

  1. Flea

    Flea New Member

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    I know the answer is out there somewhere... What is the size of the reticle ring in the RAF GM2 MkII reflector gunsight? Did they use artillery mils (1 mil = 1 meter at 1000 meters) or was it a standard milradian (360 deg = 6283 milrads)?

    The 1943 RAF Gunnery Manual (Bag the Hun) states "The span of a FW190 (and Me109, too) is such that it appears equal to a diameter of a ring when it is 100yds away." There is a 0.58m/23inch difference between the two aircraft's wingspan and the difference could be the difference between a 100mil reticle and a 106 mil reticle. I am trying to get an exact ring measurement.

    Any assistance is greatly appreciated.
     
  2. Greyman

    Greyman Active Member

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    6 degrees, 44 minutes
     
  3. Flea

    Flea New Member

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    Thanks Greyman. My math puts that at 117 milrads. Is my math off or did the Brits just pick a non-standard setting for their sights?
     
  4. Greyman

    Greyman Active Member

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    It was a '100 mph ring', which meant the radius of the circle represented the deflection allowance for hitting a target crossing at 100 mph. They had a system for it and the '50 mph ring' used in bombers for various types of shooting.

    It wasn't initially meant for judging range.
     
  5. Flea

    Flea New Member

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    Thanks, didn't know that. Do you have a reference or book that describes this more? I am familiar with using a sight for ranging purposes, but not for using it in the manner you described. I have recently developed an interest in WW2 aerial gunnery and I'm trying to learn all I can. Thanks.
     
  6. Greyman

    Greyman Active Member

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    I do, not really handy in internet form though. Basically it goes through a long, dry explanation of;
    'if target is crossing at 100 mph, put target on the ring'
    'if target is crossing at 50 mph, put target halfway to the ring'
    and so on.

    Obviously the question pops up as to how the heck the pilot is supposed to know the crossing speed of enemy aircraft. Apparently the RAF (eventually) thought the same way and trained their pilots in a more fluid, 'gut feeling' manner, as seen in 'Bag the Hun'.
     
  7. Barrakooda

    Barrakooda Member

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