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 November 20, 2011, 08:23 AM #1 hodaka Senior Member   Join Date: April 23, 2006 Location: South Texas Posts: 1,887 Binocular range finding grid question I have my grandfather's M6 WWII binoculars. They were made by Universal Camera in 1942. Does anyone know how to use the range finding grid that is found in the right lense? There are two parallel bars in the center and a vertical and horizontal axis with numbers. Google has helped me locate a number of similar binoculars, but no help with the range finding grid. Thanks.
 November 21, 2011, 05:33 PM #3 hodaka Senior Member   Join Date: April 23, 2006 Location: South Texas Posts: 1,887 Thanks Dave. That is helpful. I was thinking the parallel bars could be used to estimate range, once I get them calibrated. I will take them to the range next time and see how much height they measure at 100 yds. The numbers on the vertical scale are confusing since they show a "5" at the top then a "20" at the bottom. I was trying to make degrees of angle out of it. Since I have little need to control fire my machine guns I will simply ignore the vertical scale. Thanks again. BTW - these are surprisingly good binoculars although they have had heavy use.
 November 21, 2011, 06:35 PM #4 kraigwy Senior Member   Join Date: June 16, 2008 Location: Wyoming Posts: 10,223 I believe, (would have to see it for sure) that the marks are in Mils. With that you can estimate range. A mil is a mil whether its 10 yards (or meters) or 10,000 yards (or meters). Mils are used in Artillery and Machine Guns, (and now rifle scopes). A mil is that angle whose tangent is 1/1000, that is the angle sutended by 1 unit at a distance of 1000 units. 1 yard at 1000 yards, or 1 foot at 1000 feet. You can test this by getting a piece of string 20 inches long, tied to a target 1 inch wide. Hold one end of the string in your mouth and hold the other or pencil out. The range is 20 inches. The one inch target would be 50 mils. So M or Mil = 1000*1/20 so M or mils = 50. As a side note: Remember in basic we were taught to use fingers to estimate range. The average finger is 50 mils. You should also use your finger to cover an object. Looking at that object through your field glasses should measure 50 Mils. Lets change this to a 1 yard target at 100 yards. 1000 * 1 / 100 = 10 so the 1 yard target would be 10 mils. Knowing that, you can go the othe way. Lets say your 1 yard target is 10 mils. Range would be 1000*Target / Mils. or 1000*1 yard / mils + range to the target. 1000*1/10 = 1000 Like any other math, if you know two of the 3, you can find the third. Knowing this, you can play with your field glass and I'm sure you'll find out the marks are mils. __________________ Kraig Stuart CPT USAR Ret USAMU Sniper School Oct '78 Distinguished Rifle Badge 1071

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