What Best Defines Accuracy?

[Bart B.]

Smallest many-shot group.

Largest many-shot group.

Smallest few-shot group.

Largest few-shot group.

[chadio]

Not me with my AK at the moment

Still love the Kalashnikov, because you gotta work for it (accuracy)

[44 AMP]

The shot going where I aim it.

[stagpanther]

Me!
Me!

Largest many shot group (my statistics teacher pastes a star on my forehead)

[Pahoo]

What Best Defines Accuracy?

1) When it meets or exceeds, my expectations.
2) When I can take a second look at it and say; Wow, this thing shoots better than I can !!!

Ever finish a project and tell "yourself" that you did a darn good?


Be Safe !!!

[jpx2rk]

Does the ammo/gun combo shoot a consistently small group over several attempts on different days with different conditions. If it does, then it's "good enough". Different days will produce different results, so consistently small groups that you have confidence in hitting the target.

[reddog81]

Accuracy is determined by how far from the target you are hitting. Group size doesn't determine accuracy. Where the group is located is what matters for accuracy.

A .5" group a foot away from the target is less accurate than a 5" group centered on the target.

[Bart B.]

Originally Posted by reddog81

Accuracy is determined by how far from the target you are hitting. Group size doesn't determine accuracy. Where the group is located is what matters for accuracy.

A .5" group a foot away from the target is less accurate than a 5" group centered on the target.

Why do benchrest competitors shoot groups centered a MOA or more away from the point of aim?

[Bart B.]

https://www.outdoorlife.com/blogs/gu...jim-carmichel/

Is that gun accurate?

[Scorch]

This is the old question of precision vs accuracy. If your rifle shoots very small groups it is precise, but not necessarily accurate. If your rifle shoots where you aim but it shoots 4 MOA, it is accurate but not precise. If it shoots very small groups exactly where you aim, it is accurate and precise. I think I got that right.

But anyway, accuracy is measured on a normal curve (dispersion from POA), just like a lot of things in the world. A number of multi-shot groups would give you a statistically valid quantification of the accuracy and precision of the rifle. A lot of shooters never quantify their rifles' accuracy, they just sight it in (accuracy) and shoot for groups (precision), then choose what to tell people about it (usually smallest group). I have seen a lot of "1/2 MOA" rifles that struggle to shoot MOA consistently, but one day a few years ago when somebody's friend's cousin was shooting it, it shot them all into one hole..

I build rifles and I guarantee them to shoot caliber-sized groups with the loads I test them with (I provide that info to the customer). Sometimes customers use that data religiously, and other times they do their own thing.

[reddog81]

You're confusing accuracy and precision. The 2 terms can be used interchangeably in common language but if you are asking about precise definitions than you need to make sure you are using the correct terminology. The linked article confuses the 2 terms also.

1 shot dead center on the bullseye is more accurate than any group.

My post hit after Scorch posted... His definitions are correct.

[Scorch]

Why do benchrest competitors shoot groups centered a MOA or more away from the point of aim?

So their point of aim is not affected by bullet impact. Most people have seen this as they sight in grampa's Ole Betsy for deer season. After about 2 or 3 hits to the bright yellow/orange/red/white/whatever target dot, it is no longer a good aiming point. But if POI is deliberately above POA, your sight picture will never be affected.

[101combatvet]

Hitting the X ring consistently.

[DaleA]

I am pretty much the perfect dupe for questions like this so I'll put down my initial answer was the first choice the OP gave, Smallest many-shot group.

This was before reading any of the other posts in the thread. After reading the other posts I suspect stagpanther has the technically correct answer.

P.S. I also make a great mark for amateur magicians.

[stagpanther]

Meh, I've shot lots of .0 one shot groups.

[Shadow9mm]

ac·cu·ra·cy (noun)
the quality or state of being correct or precise.

[old roper]

Here is new record.

http://bulletin.accurateshooter.com/tag/world-record/

[stagpanther]

Why do benchrest competitors shoot groups centered a MOA or more away from the point of aim?

I'm curious--why not just take a first shot and then use the bullet's impact as the POA?

[jmr40]

I'm curious--why not just take a first shot and then use the bullet's impact as the POA?

Because the 1st shot was several inches from POA. The next shot will be several inches from that POA. If even on the target.

Everybody has different criteria. I'm 1st a hunter who just enjoys shooting as much as possible at the range. Not interested in squeezing the last bit of accuracy out of the rifle or ammo I'm looking for an average of multiple 3 shot groups shot on different days over a few months.

If that average is right at 1 MOA I'm happy. Most of my rifles and loads will occasionally produce groups under 1/2 MOA. Other times I'm just having a bad day and will get some groups closer to 1.5 MOA. That is adequate for what I do and at the ranges I shoot.

And when shooting for small groups I don't care where they impact the target. Once I'm happy with the group size I can always adjust the sights to get the impact where I want it.

[Red Devil]

Accuracy vs. Precision: Sharpen Your Shooting Skills

For me (From field positions):
Optic: < 2 MOA/few shots
Aperture: < 3 MOA/many shots

What then is a good field marksman? - Jeff Cooper

Does a soldier need to shoot well? Good question.
I know of three cases in which excellent fieldmarksmanship decided the action.
These were the Boers at Majuba Hill, the US Marines at Chateau Thierry,
and the Volksturm reservists at the Arnhem bridgehead.
There may be other such cases, but if so they are notwidely documented.
Chroniclers are rarely interested in battle techniques,
so the fact that something is notreported certainly does not mean that it did not occur.
Nonetheless, good field marksmanship is a rarity − in or out of uniform.

What then is a good field marksman?
In my opinion, a man who can hit a tea cup at 100 meters with his firstshot,
from a field position, in a 5 second interval is a good shot.
Try this test on yourself, but do not call forwitnesses.
People who talk about good shots are usually terrible liars.

Red

[JohnKSa]

This is maybe 4 different discussions wrapped up into one thread.

The OP's original question is about statistics.

There are also discussions about:

1. The definition of 'accuracy' vs. 'precision'.
2. The definition of 'practical accuracy'.
3. Common practices in benchrest competition.

What could possibly go wrong?

[Colorado Redneck]

Accuracy is term that can be used to describe actions. Examples like accuracy in accounting, accuracy of reporting, accuracy of predicting have nothing to do with shooting. Bart was asking about how the term applies to shooting. The definition of accuracy is "the quality or state of being correct or precise." To answer Bart, correctness or precision beg definition. I'm my humble opinion, accuracy of a shot is best described as hitting a target where the shooter intends.

[stinkeypete]

The best definition of accuracy is “how close does each bullet hit, compared to where I was aiming, for every shot of a comparable set.”

The sets that are compared could be things like “for this exact load” or “during this competition” or “on this day” or “at this exact temperature and atmospheric pressure and wind” etc etc including every combination one can think of.

Locations can be measured in the Cartesian system (x,y,z) which is (length, width, height) or in polar coordinates (r, theta, phi).

Polar coordinates may seem more complicated but are a powerful tool for many applications, especially when dealing with circles, balls, the earth, astronomy, and when pointing at things.

The Cartesian system is named after Renee Descartes, French mathematician who invented GRAPHING in about 1625 or so. Until then, no one knew how to make a graph, everyone used tables.

It should be noted that Descartes, being really smart, didn’t feel restricted in using coordinate systems that were orthogonal… that is, his x, y and z didn’t need to be at right angles to each other. He could define the transformations and then graph away, for his particular data, and understood what it meant.

Being really smart like that, not many other people could figure his graphs out.

After Newton invented the cookie, Billybob Polar invented the Polar system. In this case, we could compare all bullet hits for all ranges by measuring the angular deviation… beta squared = theta squared + phi squared.

Strictly speaking, the famous marksman Pythagoras shot at the inside spherical section with a radius of 100 strides, so his misses were at the same range as his exact hits. It’s only because of shipping and manufacturer demands that we notice that for very large radii, a flat target’s radius squared= x squared + y squared + z squared results that within practical measurements was the same as x squared. Around 1910, the Government started doing accuracy tests at oh-about-waaaaay-far for the .30 cal Springfield using flat paper targets.

Long story short, in the Polar system, deviation between point of aim and point of impact, independent of target distance, is most easily measured in angular deviation.

The French, wanting to gamble, invented statistics. This way, they did not need to measure the impact of every bullet and could get on with playing cards, drinking wine and wearing berets.

Oh, we use a system of degrees… 360 degrees per full rotation
‘Minutes’… 60 minute per degree (‘) and
‘Second’… 60 seconds per degree
Because of the Slide Rule, which says “give me a few hundred years to invent the decimal system and a few hundred more to invent the calculator.”

Base 60 is very good when using fractions- it’s divisible by 2,3,4,5,6 and 10 by old farts who learned the times tables. Having done that, we pull out our phones like normal people when dividing real world numbers.

Us old farts insist that “accuracy” and “precision” are distinct and very important different concepts, often confused.

An accurate rifle shoots a tight group on the X
A precise rifle shoots a tight group low and to the right… correctable later.
My new shotgun is accurate but horribly not precise… the huge even widely spaced group is centered on the x.

[Road_Clam]

Month to month consistency , and minimising those "uncalled" random fliers.

[tangolima]

The probability of hitting an intended target. Other than that it all entertainment, winning a match, breaking a record and all that.

-TL

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