MOA vs MIL

Shooters argue about MOA versus MIL the way they argue about 9mm versus .45. The argument is mostly cultural. Both systems divide a circle into angular units, both work perfectly well at any distance, and the precision difference between them is far smaller than your ability to read wind. What actually matters is internal consistency — and understanding what the numbers physically mean so you stop memorising conversion tables you'll fumble under time pressure.

What a minute of angle actually is

A circle has 360 degrees. Each degree splits into 60 minutes. So one minute of angle is 1/21,600th of a circle — a genuinely tiny wedge.

Project that wedge out to 100 yards and it subtends 1.047 inches. Almost everyone rounds this to one inch, which is why you'll hear "MOA is inches at 100 yards." That rounding introduces about 4.7% error. At 100 yards that's nothing. At 1,000 yards, a 30 MOA elevation dial is off by roughly 14 inches if you did the maths with the rounded number. That's a miss on a torso target.

The rounded version is called shooter's MOA or IPHY (inch per hundred yards), and a small number of scopes are actually calibrated to it rather than to true MOA. Check which one you own.

What a milliradian actually is

A radian is the angle you get when the arc length equals the radius. There are 2π radians in a circle — about 6.2832. A milliradian is a thousandth of that.

The useful consequence: one mil subtends one unit at a thousand units of distance. One metre at 1,000 metres. One yard at 1,000 yards. One inch at 1,000 inches. This is not a coincidence or an approximation — it falls straight out of the definition, and it is why mil-based ranging maths can be done in your head.

At 100 yards, one mil is 3.6 inches (100 yards is 3,600 inches; a thousandth of that is 3.6). At 100 metres, one mil is 10 centimetres exactly.

The conversion, and why you should avoid needing it

One mil equals 3.438 MOA. One MOA equals 0.2909 mil. You can memorise those, and you will get them wrong at some point.

The better answer is to never do the conversion at all. The most common real-world failure is a mil reticle with MOA turrets, or vice versa. You spot a miss, measure the correction in the reticle as 1.5 mils, then dial 1.5 on a turret that's counting quarter-MOA clicks. You have just applied about 0.44 mils of correction and you'll wonder why the round barely moved.

Buy matched. Reticle and turret in the same unit, on every rifle you own if you can manage it, so the muscle memory transfers.

Click values, and what "1/4 MOA" buys you

A quarter-MOA click is a finer adjustment than a tenth-mil click — roughly 28% finer. This is the one genuine technical difference, and it is the entire basis of the "MOA is more precise" claim.

In practice it rarely decides anything. At 1,000 yards you are choosing between a 2.6-inch increment and a 3.6-inch increment on a target where your wind call is worth a foot or more of error. Group size, ammunition consistency and atmospheric reading swamp the difference. Benchrest and F-class shooters working with genuinely tiny groups are the population where an eighth-MOA click earns its keep.

Ranging with the reticle

Mils win here, decisively, and this is the real reason military and precision-rifle shooting standardised on them.

The formula for mil ranging in yards: (target size in yards × 1000) ÷ mils read = range in yards. A 20-inch-tall target is 0.556 yards. If it measures 1.4 mils in your reticle, the range is (0.556 × 1000) ÷ 1.4 = 397 yards.

In metric it's cleaner still: (target size in metres × 1000) ÷ mils = range in metres. A 1.8-metre-tall person measuring 3 mils is at 600 metres. That's arithmetic you can do while looking through the scope.

The MOA equivalent requires the 95.5 constant — (target inches × 95.5) ÷ MOA = range in yards — and it is simply harder to do quickly and correctly.

Laser rangefinders have made reticle ranging much less critical than it was, but reticle ranging still works when the laser can't get a return, when the battery is dead, or when the target is partially obscured.

So which one

• Shoot with other people? Match whatever they use. Being able to say "come up point-four and hold two left" and be understood is worth more than any technical edge.
• Precision rifle competition, or anything with a spotter? Mils. It is effectively the standard, corrections are called in mils, and the ranging maths is cleaner.
• American hunting tradition, thinking in inches, mostly inside 400 yards? MOA maps intuitively onto inch-at-100 thinking and there is nothing wrong with it.
• Benchrest, F-class, load development at short range? MOA with eighth-minute clicks gives you finer resolution where it can actually be measured.
• Genuinely undecided? Take mils. The base-ten arithmetic is easier under stress, and the wider ecosystem of ballistic apps, training material and competition norms assumes it.

The check nobody runs

Whichever system you pick, verify your scope actually delivers it. A scope that advertises 0.1 mil clicks and delivers 0.093 will be silently 7% off — invisible at 100 yards, a clean miss at distance. The tall target test takes twenty minutes and tells you your true click value, and it is the single most useful thing you can do with a new optic.

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