Rifle Scopes Mrad IS Meteric

[3DHUSKER]

I use (JB) jelly beans to measure and dope now, it is neither standard or metric. see signature.
I have learned that the easy way to convert anything to metric is to double it and add 30. For example: 5 measured in anything converted is 40 metrics. Its so easy.

 

[BM3JOHN]

So,,Canadian Sniper Rob Furlong really made his shot at 12.8 Furlongs then... I think I'll sit back down now .

 

[3DHUSKER]

That is 55.6 metrics .....that's a long shot.

 

[Kiwigrunt]

That is 55.6 metrics .....that's a long shot.

Not if he used a 5.56
That's only out by one decimal.
Now if he used a .223 it would have been a different story.

 

[Pinecone]

Wow, y'all sure know how to make a guy fee welcome! I count myself lucky that nobody flamed me for spelling errors. Yeah, I probably do need to get out more, but that's one of the pitfalls of working from home.

Does anyone want to argue with me that decimals or fractions are easier to calculate than whole numbers? Sure you can measure ANYTHING using ANY measuring system; I am exactly 0.0011679292929293 miles tall, but who wants to work with a number like that when there are easier and more convenient scales to use and when rounding introduces significant errors? That's why they invented scientific notation (and the metric system), to make large numbers and decimals look and function like smaller whole numbers in calculations and equations.

While converting units is a snap with the metric system, using metric units in everyday calculations is not necessarily easier. The problem lies in the fact that each metric unit of measurement is an order of magnitude smaller or larger than the next unit. Often times the things to be measured fall somewhere between two measurement units, so you end up with a result that is either needlessly precise or hopelessly inaccurate.

I tried to illustrate that point in my previous example, but apparently failed, so how about this:

If a highway lane is 12 feet wide and there are six lanes, how wide is the highway? How about if the highway lane is 3.7 meters wide? The distance is the same but the calculation is easier using the measurement scale originally designed for measuring such things. Which number is easier to use in calculations, 72 or 22.2? Furthermore, a rounding or measurement error of one full unit won't make much of a difference in the usability of the highway if you're measuring in feet, but could be a problem if you're measuring in meters. I realize that these kinds of errors can go both ways, but most "non-metric" measurement scales were created to measure specific things to a reasonable level of accuracy, so those units naturally "fit" the items being measured (think 1/4 carat diamond versus a 0.05 gram diamond). I agree that a lot of this is "Legacy" or tradition, but there is a reason why those measurement systems were originally developed and why they are still in use, they work.

But back to my previous example. Let me clarify. Something weighing "2.8g" on a scale accurate to within a tenth of a gram could actually weigh anywhere from 2.75g to 2.84g. Likewise something weighing "2.89g." on a scale accurate to within a hundredth of a gram could weigh anywhere from 2.885g to 2.894g.

True, the difference between 2.89 grams and 2.90 grams is only 0.01 grams (0.15 grains), but the difference between 2.8 grams and 2.9 grams is 0.1 grams or about 1.5 grains, so you could achieve acceptable loading accuracy if you had a powder scale that measures in grams to hundredths of a gram but not one that only measures to tenths of a gram.

Adding digits behind the decimal will make any metric measurement scale work, but it also adds to the confusion (as my powder weight example illustrates).

I stand by my assertion that there is little difference between 44.6 and 44.7 grains while there is a huge difference between 2.8 and 2.9 grams. Just to be clear, a tenth of a gram is equal to about 1.5 grains.

My load data books give the following start and max loads for a 150 gr. Spitzer with BLC2:
Data Source-Start charge grains/Start velocity fps-Max charge grains/Max velocity fps-Difference grains/Difference fps
Sierra-40.6/2500-48.7/2900-8.1/400
Lyman-45.0/2717-49.0/2915-4.0/198
Speer-40.0/2518-44.0/2753-4.0/235
Hodgdon-45.0/2661-48.0/2839-3.0/178

A 1.5 grain disparity in powder charges my not create a 150fps variance,but it will create enough of a variance that it falls outside the standard deviation for a string of "identical" cartridges. And this is just for the single hypothetical example listed. What would the difference in velocity be between a .45 ACP 230gr. bullet loaded with 5.0 grains and 6.5 grains of Red Dot?

I concede the point that some European ammunition manufacturers DO include bullet weights in grams. I just looked at a box of GECO 9mm in the safe and it was marked in grams, but my Silver Bear 54R was not (no doubt it was packaged specifically for us dumb Americans).

I'll also concede that many (most?) of the modern (post 1799) firearms dimensions in "inches" could be/are conversions from metric

But to get back to the original-original reason that led me to this thread, I have an IOR compass marked in "Russian" mils. Can anyone tell me if this system is used in any optics? Also can someone tell me the difference(s) in subtension from a regular (U.S.) mil-dot. I was originally disappointed when I realized what scale was on the compass, but I'm thinking about building a faux Mosin-Nagant "sniper" and might just keep the compass as an accoutrement for the rifle.

Any info would be greatly appreciated.

You also use the fallacy used in the US when trying to convert to metric. A road lane does need to be 12 feet (3.7 m) wide. You change that to the nearest usable EVEN metric number. 3.5 m or 4.0 m wide.

When the US tried to convert to metric, they did speed limit signs in even English measurements and odd ball metric measurements. They should have rounded to the nearest even metric. So instead of 60 MPH/97 KPH, round to 100 KPH and mark the signs 100 KPH/62 MPH.

Just like was done with liquor and sodas. No one thinks twice about buying a 750 ml, 1l, or 1.75 l or booze. Or a 1l or 2l soda.

Why would reloading scales NOT be to the hundredth of a gram? It is basically the same actual weight increment as 1/10 grain. Going to a hundredth of a gram is NOT making the scale harder to make or harder to use or more expensive. Remember 0.01 gram = 0.15 grain.

As for your height in miles, how much trouble was that, and did you have ot use a calculator? I am 1.803 m tall. In kilometers, that is 0.001803 km. EASY, done in my head.

 

[Graham]

Mrad IS Meteric

There's nothing metric about Mils.

However, due to this confusion I recently heard that the Russians have switched to measuring their sniping increments in MON: Millions of Nazis.

 

[3DHUSKER]

There's nothing metric about Mils.

However, due to this confusion I recently heard that the Russians have switched to measuring their sniping increments in MON: Millions of Nazis.

1 MON = 32 METRICS..... This is so easy..

 

[270Win]

I often see guys saying milliradians aka mrads are not metric. I can understand wanting to say it isnt as we often use it with yards and inches however a milliradian is equal to 1/1000 of a radian. A radian is a SI derived unit and therefore part of the metric system. If my logic is completely off here feel free to let me know I won't be offended just figured I would point it out since anytime you see someone mention mrads and metric a half dozen people comment that mrad isnt metric.

I utilized Wiki as a refrence only because I have spent plenty of time reading more indepth painful refrences to confirm what I found on wiki and wiki is a little easier to read.

Angular Mil definition: Angular mil - Wikipedia, the free encyclopedia

Radian Definition: Radian - Wikipedia, the free encyclopedia

Dividing something by 1000 does NOT make it metric and the radian is not based on the meter

 

[Kiwigrunt]

We have identified – as per some previous posts – an area of potential confusion in the 'degree based' scopes pertaining to true minutes versus iphy.

So here's a question for the scopy scientists among us. Are metric p) scopes calibrated based on true trigonometric mrads – of which there are 6283 in a circle, or are they based on 'NATO' mils of which there are 6400 in a circle? I always thought it was the first, but the angular mil link quoted in above post suggests the latter. The latter would also be more consistent with common notation. It appears (I am still confused here) that the notation for trigonometric milliradians is mrad, while for military milliradians it is mil.

It probably makes so little difference as to be practically irrelevant. Just interested.

 

[Bender]

I forget how many there are but pretty sure most all new Mil/Mil scopes are based on the Marine mil? The army had a diff mil but went with the marine mil later? I could have that backwards and I don't remember the mil count. So there. How is that for mud in the water.....