'nuthead',
You make a good point about the interchangeability of yards and metres using the Mils ratios of angle, but for the suggestion that Mils is not Metric I am going to respectfully disagree.
Mils, or Miliradians is an angular system of measurement derived from SI (International System of Units). SI specifies seven standards of measurement which all other measurements are derived (called SI Derived Units). The standard measurement for area is the square metre (Metric). Mils, which are 1/1000 of a Radian is an SI Derived Unit of angular measurement based on the metre...Metric.
Mils is Metric, in the same way that Lexus is Toyota and Maybach is Mercedes. They are all subsets of a more senior and related concept.
We don't use the exact mathematical subdivision of Radians because that does not lend itself to the Decimal system. The exact subdivision of the circle in radians is 6,283.185, or in other words 62,831.85 Mils. So, depending on what you are doing (shooting, artillery, mapping) and where you live we round this up or down for ease of decimal calculations. 64,000mils is a complete circle on my Silva compasses. The Russians round it down to 60,000mils for ease of use on a watch face (100 mils = 1 minute of a clock face). The Swedish use 63,000Mils and call them Streks.
I agree with you however, that the different conventions of rounding up or down of this Metric system of angular measurement to conform to the Decimal system are interchangeable between Imperial and Metric. 1 mil of angle subtends 1 metre of length at 1,000metres distance, and all permutations of that. But so too does 1 mil subtend 1 yard at 1,000 yards, and all permutations of that. If you are used to working in feet and yards then by all means stick to what you are familiar with, as long as you are aware that the subdivision of lengths within the Imperial system are not Decimal.
You make a good point about the interchangeability of yards and metres using the Mils ratios of angle, but for the suggestion that Mils is not Metric I am going to respectfully disagree.
Mils, or Miliradians is an angular system of measurement derived from SI (International System of Units). SI specifies seven standards of measurement which all other measurements are derived (called SI Derived Units). The standard measurement for area is the square metre (Metric). Mils, which are 1/1000 of a Radian is an SI Derived Unit of angular measurement based on the metre...Metric.
Mils is Metric, in the same way that Lexus is Toyota and Maybach is Mercedes. They are all subsets of a more senior and related concept.
We don't use the exact mathematical subdivision of Radians because that does not lend itself to the Decimal system. The exact subdivision of the circle in radians is 6,283.185, or in other words 62,831.85 Mils. So, depending on what you are doing (shooting, artillery, mapping) and where you live we round this up or down for ease of decimal calculations. 64,000mils is a complete circle on my Silva compasses. The Russians round it down to 60,000mils for ease of use on a watch face (100 mils = 1 minute of a clock face). The Swedish use 63,000Mils and call them Streks.
I agree with you however, that the different conventions of rounding up or down of this Metric system of angular measurement to conform to the Decimal system are interchangeable between Imperial and Metric. 1 mil of angle subtends 1 metre of length at 1,000metres distance, and all permutations of that. But so too does 1 mil subtend 1 yard at 1,000 yards, and all permutations of that. If you are used to working in feet and yards then by all means stick to what you are familiar with, as long as you are aware that the subdivision of lengths within the Imperial system are not Decimal.