Understanding Your Groups

How to evaluate precision and accuracy — where is my 1/3 MOA?

Is it better to shoot steel or paper - and why does cardboard matter? Why do manufacturers guarantee “super precision” and what does it really mean for your results?

Varied training - shooting at different targets in interesting locations - allows you to build good cooperation with your rifle. The target is not a problem if you know your rifle’s capabilities… and your own 🙂

I fired four shots into the central 10-ring at 100 m. They formed one slightly stretched hole - almost a single impact.

Let’s assume the target below shows that situation.

Now I want to evaluate my precision. The tighter the impacts are grouped, the higher the precision. As a reference we use 1 MOA - a circle about 3 cm at 100 m (a simplification - technically ~2.9 cm).

In my own training I use the 3 cm value and I do not mathematically rescale it for longer distances. For evaluating my results this level of accuracy is fully sufficient, and extra calculations add no real value to the training process.

Simple equipment solutions - like a bubble level - help avoid errors that are sometimes hard to interpret: I aimed very precisely, yet the impact was right and low.

Precision is usually measured in two ways.

The first method measures the distance between the outer edges of the two most distant impacts. On the target above, the black squares are 25 mm. If the largest outside-to-outside spread is 10 mm, that equals roughly 1/3 MOA.

Why? Because 1 MOA is about 30 mm at 100 m - and 10 mm is roughly one third.

The second method measures center-to-center distance. On this target it would be harder to do, but the result would be slightly below 1/3 MOA.

For many shooters, precision is not necessarily about using a ruler and calculating a 1 cm shift.  Metal targets are worth trying - you hit, you see or hear it, and you don’t have to measure.  Additional variables - placing targets in less obvious ways - can make training more engaging.  It’s worth practicing different approaches, among other things to find the one that works best for you.

Which method is better?

It depends. I personally use the first one - faster and simpler. The slightly “harsher” evaluation is not a problem for me. The second is more precise and useful when comparing different calibers.

Let’s evaluate another target.

Before reading further - calculate how big 1 MOA is at 300 m. Distance: 300 m. Grid: 1 cm.

1 MOA at 300 m is about 9 cm (simplified).The upper group spread is ~4.5 cm → about 0.5 MOA. The lower group ~3 cm → about 0.3 MOA.

Quick exercise

What turret correction should I make to improve accuracy in the upper group?

Accuracy = how close impacts are to the aiming point.

First step: determine Mean Point of Impact (MPI). I connect pairs of impacts, find midpoints, then their intersection.

MPI is 4 grid squares - about 4 cm - above the center.

Turrets are in MILs.1 click = 0.1 MIL.0.1 MIL at 100 m = 1 cm.0.1 MIL at 300 m = 3 cm.

So one click moves MPI 3 cm at 300 m.

Decision: 1 click DOWN.

A rifle rated as sub-MOA from the factory may, over time, lose precision. A very likely cause is fouling. It’s worth learning how to properly clean precision rifles, because this will be necessary from time to time in regular shooting practice.

Back to precision.

The farther the distance, the larger the 1 MOA area becomes. At 700 m it is about 21 cm (simplified).

Six shots grouped within an area smaller than 3 cm at 100 m equal 1 MOA - just like six shots grouped within an area smaller than 30 cm at 1 km.

Rifle precision

Some manufacturers state “sub-MOA at 100 m”.

Usually this means that in controlled conditions, with selected ammunition and a fixed setup, the group fits within 1 MOA.

Mathematically you could scale it:

500 m → <15 cm2 km → <60 cm

But this is only mathematical scaling. At long distances ballistic factors, atmospheric conditions and transonic transition make linear scaling unrealistic.

What matters for you:

If you know your rifle’s real precision and it is below your expectations - accept it or change equipment.

The reticle - one of the best tools of a precision shooter. Training with it offers wide possibilities that should always be continuously refined.

Does the rifle guarantee accuracy?

No.

A rifle can be precise - but accuracy depends mainly on the shooter.

You can shoot very tight groups in the wrong place - precise but inaccurate. You can also have impacts centered but widely spread - relatively accurate, but not precise.

Precision and accuracy are two different things.

A common beginner’s mistake: I’m not precise or accurate? I’ll buy a better rifle. A bigger caliber or more expensive equipment will never replace consistent training.  If the result on the target is not what you expected, in most cases the reason is the shooter - not the equipment.

How I train at longer distances

I mainly shoot four-shot groups because they are readable enough for my training goals.

Sometimes I fire a single cold shot - to test myself in a sniper context. Sometimes I shoot ten-shot groups - when I want to see how I perform in a more sport-like format.

Number of shots is a tool, not a rule.

I introduce corrections only after three groups. Each group is evaluated separately, but I do not adjust turrets after every series.

800 m

At 800 m, 1 click (0.1 MIL) equals 8 cm.

A rushed correction can easily move you… onto your neighbor’s target.

Why cardboard matters

A large surface lets you see where you actually hit if you miss the central aiming point.

I staple a large cardboard sheet and place an A4 target in the center. If I miss the A4, I can still read impacts on the cardboard and calculate corrections.

Simple solution - but very effective.

A typical use of a cardboard backer larger than the target — it makes it easy to spot hits that didn’t land on the small target.

Steel vs paper

Steel plates can significantly speed up training - if their size matches the distance and the training goal.

In sniper-style training I consider them more useful than spending half an hour analyzing millimeter differences on paper.

I do not treat this as the only correct method. It is simply what works in my training and within my assumptions.

Working as a well-coordinated team is one of the most effective ways to get real satisfaction from training.

Are your results good?

It depends on why you shoot LR.

If your goal is competition - your training model will be different. I describe how I evaluate my own training.

1/3 MOA is mathematically better than 1.3 MOA. But try to repeat 1.5 MOA at 800 m - you may find that 2 MOA is already a very solid result.

Diana 75, 70 shots at 10 meters. Good precision and good accuracy — the result of patience, trigger work, and consistency.

Good luck.

About the author 😊Usually hits where he aims. Still learning - and happily taking all the teasing, confident that every sarcastic comment comes from the best intentions 😊.

Shooting, like any activity, is at its best when it brings enjoyment instead of unnecessary tension. During dry training, Mrok often helps 🙂

Have you made it this far?

Here I’m showing the beginning - my long-standing love for air rifles. I shot a small air rifle as a child. Back then, I only wanted to hit the target. Later, I began to understand how many factors influenced all those misses that used to frustrate me.

1 MOA at 100 m is about 3 cm. These targets are 2.5 cm in diameter, and I shoot them from 10 m. Each one received three shots. With a bit of luck, all three pellets pass through a single hole - perfect precision, but…If you calculated correctly, 1 MOA at 10 m is only 3 mm. My three-pellet hole is about 5 mm - which makes it close to 2 MOA 😉

As an adult, I bought what was a dream rifle for many shooters in the 1980s - the German precision rifle Diana 75. Later, I spent a long time searching for a Diana 100 in collector’s condition. These rifles, even though they are nearly 50 years old, are still perfectly precise.

I have both of them. Both in excellent condition. I still shoot them regularly because I believe it’s hard to find better trigger training.

Diana 100. A diopter is a kind of simplified version of a scope - it doesn’t magnify the image and it has no reticle, but… it does have two adjustment knobs that work just like those on a precision rifle scope.

I run different training sessions, with different types of targets. The pellet in an air rifle is slow - especially in rifles like mine. They are unmodified sport rifles with very low energy.

A slow projectile in this type of rifle immediately exposes mistakes in position and any uncontrolled movement.

5 mm targets at 10 meters. Pellet diameter: 4.5 mm.

I remember my first plastic toy gun - it shot something, but I desperately wanted to hit the target like the heroes in the movies. It never really worked. Then I made myself a bow - and suddenly I was both more precise and more accurate than with that plastic gun.

A rifle was every boy’s dream. The Second World War had ended only 25 years earlier, so firearms still lived in stories and on cinema screens.

I always liked to dream. And when I grew a little older, I decided that dreaming is essential - because dreams are what give us goals in life.

Today I shoot with rifles I truly like - and I value them also because they keep me motivated to train. I cannot stop, because that would mean I have stopped dreaming 🙂.

Diana 100 - a single-stroke pneumatic (PCA) rifle. At the end of the barrel sits a barrel weight with a tunnel front sight. Combined with a diopter, it creates a highly precise sighting system. A true competition-grade sport rifle.