Unidentified scope-military?

[gunner]

Hi Patrick,

here`s a Link to the scope.

Mosin Nagant M91

Regards

Gunner

[jmoore]

Well down in the article that Gunner references is a picture of a Finnish captured scope w/ an external clicker. So maybe that's where your scope went at one point. Had not seen that mod before!

Thanks, Gunner!

I bought one these scopes loose back around 1983 and still haven't finished putting it on a rifle. The reproduction side mount dovetail assembly doesn't lock up tight , so that project gets ignored....Hate to just shim it or otherwise cobble it up, but haven't felt like whittling out a new base.

[gunner]

My pleasure !

Gunner

[Patrick Chadwick]

The lateral scale will probably be in mils.

Please, what are mils?

Patrick

[JBS]

In target shooting, the mil is often understood to mean 0.001 radian or 1 milliradian, which is about 0.0573° or 3.43775 moa. In Britain, the term angular mil generally refers to the milliradian. 1 milliradian corresponds to a target size of 10 millimeters at a range of 10 meters, or 3.6 inches at 100 yards.

stollen from another sight

[Alan de Enfield]

Please, what are mils?

Patrick

The mils system has been around since the beginning of the twentieth century, but the American military formally adopted it in the 1960's and it is now widely used, in one form or another, by most armies worldwide.

Measuring angles is important for navigation, map making and artillery, all of which are very important in the military world. The measurement of angles is the area of mathematics known as trigonometry, or geometry.

There are two pi radians in a circle, where pi is the ratio of the diameter of a circle to its circumference. Pi is roughly equal to 3.1416, but the decimal places go on to infinity, it is an irrational number. Simplistically explained, one pi radian is a segment of a circle that has a rounded edge that is the same length as the straight sides.

From the radian we get the mil, or mil-radian. This is another unit used to define angles. These are used by the military because an angle of n mils is n units wide at a distance of 1000 of the same units. So when viewed at 1000 metres a 3 metre long vehicle will appear to be 3 mils in length.

There are 6283.1853 mils in a circle, but the U.S. military standardised this to 6400 mils to simplify things, so that North is seen as 6400, South is 3200 and so on.

The Russian and Arab countries decided to make things even easier, and they developed compasses with 6000 mils, which look just like a watch face. North is 6000 or zero, East is 1500, South is 3000, West is 4500 etc., just like minutes on a watch face. These compasses have been produced by Francis Barker since the early 1970's and are called the DICI model.

The mils system fits in well with artillery, rifle and binocular optics that have reticles or graticules, scales visible in the sights that work as distance markers. A man, who we can assume to be approximately 2 metres tall, seen through an optical sighting system as 4 mils tall will be at 500 metres, but if he was seen as 1 mil tall he would be at 2000 metres distance.

The French came up with an idea to make a compass with 400 units or "grads" but it never really caught on, and Francis Barker never produced any.

Another variant is the 'metric circle'
Some years ago I was teaching orienteering to some boy scouts from Norway, they continually headed off on the wrong heading, after calling them back several times I decided to have a look at their compasses, they had 400 degree compasses (as we all know there are 360 degrees in a circle, so a heading of 360 is due north), on their compass, East was 100 degrees, South, 200 degres, West 300 degrees and North 400 degrees. It caused some problems.

[Peter Laidler]

That's the VERY reason you never, never but NEVER give an Army Officer a compass. You should never even trust him with a map either. I kept a compass around my neck and tucked (very deeply) in my pouches because it looked like I knew what I was doing. But when given a map, I always passed both to one of the drivers who really did know what he was doing.

But 600 and 400 degree compasses, well, that's probably what I'd been using!

[jmoore]

So, if this scope has "mil" windage, and I don't really remember, then its 10cm adjustments at 100m. That seems correct, maybe I'll throw mine on the collimator this weekend, if no one else gets this question of high importance sorted first!

[jmoore]

Yup, the scale works out to about 10cm increments on the windage scale, so mils is equivalent.