Can you define accuracy?

T

The Terminator

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While I was at the range with my Savage bench/sniper rifle this Saturday, I was wanting 1/2" or less groups at 100 yds. A fellow sat down beside me and was getting 3 inch groups, shooting on his elbows, and firing about every 10 seconds once he put the rifle to his shoulder. He is the one that amazed me. I think that he was shooting better and more accurately than I was doing. I was using bags, and taking my time. He was shooting a regular .270 bolt action hunting rifle. 1 1/2 or 2 inch groups are good enough with my 45/70 at 100 yards. So, what is accuracy? Is it a function of the shooter, or the gun, or both?.
 
when you hold the gun thats marksmanship. when you put bullets through the same hole off a rest thats accuracy.

just my .02
 
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Accuracy versus precision

Please see the attahed file for a suggest clarification.
 

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I follow Fred's definition..
I'll add that 'Accuracy' is generally a misnomer in benchrest circles.

Some of the tightest LR benchrest record 'groups' have printed relatively poor as far as accuracy. Just look at them.
.1moa taking trophies .75moa from center of mark..

So was the dirty 270 shooter truly more or less accurate than you?
 
Mike

There is a reason most of the groups aren't centered in the center or bulls eye.
If the group is centered you destroy your aiming point.

Hal
 
Competition Accuracy vs Precision

Mike and Hal,

In my attachment I was attempting to relate the definition differences using target illustrations typical of the casual local range shooter. However, if we want to apply the definition differences to Benchrest matches then we can use score versus group:

Group - size of group per center-to-center of widest spread pair of a group of five shots (anywhere in the top or record half of the target).

Score - score value determined by distance from center (X) of target (for HBR one shot on each of the five scoring sections).

I'm intentionally evading any discussion of hold off and will stick with:

Accuracy = offset from point of aim – of point of impact for single shot – of center of group for a group of shots

Precision = dispersion of shots within a group – typically the center to center distance of the two most widely spaced points of impact of shots in the group
 
I think you need to add one more important consideration-- "expectations."

What do you have a reasonable right to expect?

If I were that .270 guy with the 3" groups, I think I would be selling myself short. He should get no less than 1.5 " groups if he has a quality sporter rifle. Even with factory ammo. I would ask no less, or I would sell that rifle.

I have a 22-250 varminter, and I can pretty much count on 3/4" groups. Sometimes a lucky group will surprise me. I can fire half a dozen 5-shot groups and count on an overall average of under 1 MOA. If you discount a lot of the boasting and hot air on this forum, and look at reality, that is a good-shooting varminter.

For a true BR gun, the expectations would be much higher. With a Hart of Shilen barrel, 3/4" at 100 yds would be a great disappointment.

So you see, add "reasonable expectations" to your recipe for accuracy.

If you don't get the results you expect -- or demand -- work on refining your loads.
 
Certainly sounds like YOUR 'expectations' relate solely to precision, rather than accuracy.

For all we know, the 3" grouping was producing 1.5" of accuracy, which ain't bad -off hand with a less precise hunting rifle.

I believe hunters get too worked up over grouping, and should focus instead on accuracy. That is, the load producing tightest single shots with respect to the center of mark. With this, a shot gun pattern 1" across the bull @100 may be adequate at 1/2moa of accuracy.

That in my view is needed for varmint hunting.
1moa of accuracy(regardless of grouping) won't get it unless they are very very big 'varmints'.

I don't hold stock in 'center of group' as defining accuracy anymore than SD for load development.
Here, more than anywhere, ES matters.
 
Accuracy is the ability to consistantly put the bullets where you want them. That could be into a small group ctc, it could be putting them all in the X ring, or it could be running one bullet into the vitals of whatever you are hunting.
 
No..
'Accuracy' is well enough defined with ANY furthest single shot -from center of mark.
'Consistency'(or precision), must include EVERY shot in the required count -to define a group -irregardless of center of mark.

Score shooters would strive to be consistently 'accurate'.
Group shooters would strive for 'consistency'(or precision), -rather than accuracy.
Hunters would strive for the proper single shot, within their accuracy potential.

There is a difference between consistency and accuracy, that might be bridged, but should not be taken as synonymous..
A 1/8" group indicating 3/4" furthest POI from center of mark, is no better than 3/4" in accuracy. And 1/2" accuracy might indicate grouping from 1/2" all the way out to 1".
 
While I was at the range with my Savage bench/sniper rifle this Saturday, I was wanting 1/2" or less groups at 100 yds. A fellow sat down beside me and was getting 3 inch groups, shooting on his elbows, and firing about every 10 seconds once he put the rifle to his shoulder. He is the one that amazed me. I think that he was shooting better and more accurately than I was doing. I was using bags, and taking my time. He was shooting a regular .270 bolt action hunting rifle. 1 1/2 or 2 inch groups are good enough with my 45/70 at 100 yards. So, what is accuracy? Is it a function of the shooter, or the gun, or both?.

Its a function of everything.
Some people just have all the right physical and mental properties to be a good shot.
Then you put an accurate gun in thier hands and wow something special happens.

I will give you an example . A distant cousin came out from England on a holiday . He was a computer programmer and a city dweller and had never traveled anyplace before and never ever handled a gun before.
I took him out bush and set up some targets and let him fire some of my guns.
He amazed me , once he got the idea of how to stand and hold the gun and focus the scope picture he was away. He could shoot bettter offhand than me. The really amazing thing was that with another certain type of gun he was a natural.
He was so tickled that he could do something like that, that he went back to England and eventually joined the Police force.
In training he fired the best hand gun groups that the training instructors had ever seen from a recruit.
12 month ago he had not even touched a gun.
You can't compete with that and you can't teach it , it' s a god given skill.
Just like some people are born with the ability to play a piano.
 
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Accuarcy is in the beholder...

I have a customer who shoots prone 600-1000 yards. Of course he cann't practice every week at 1000 yards. He practices at 100, and 200 yards. He shoots any/any class, for those who don't know what that means he shoot a 6mmBRX, with a 25X scope, wearing a shooting coat and a sling. He shoots his rifle off a rest before every match. His accuracy goals at 100 yards are a ten shot group within .3' to .4" with an extreme velocity spread of less than 10fps. His personal shooting goals are to shoot a twenty shot group using a sling off the mat under .7". He does this week in and week out. Two weeks ago I saw him shoot two clean 200 points at 1000 yards shooting a highly modified Savage model 10. In my opinion equipment is about 40% of the game and shooting skill is about 60%. I see shoters like Kent Reeve, Norm Crawford, shoot a 308 Palma gun with Iron Sights shoot higher scores than most with scopes. In this last 1000 yard match a young shooter named Jeff Rorer who shoots F-TR (restricted to 223 or 308) beat most if not all of the F-Open shooters. He has good equpment, he practices regularly and his shooting skills have improved meaning, he is learning to read the wind.

In my opinion a good shooting rifle in the hands of a skilled marksman is the man or woman to beat.

Rustystud
 
I think you need to add one more important consideration-- "expectations."

What do you have a reasonable right to expect?

If I were that .270 guy with the 3" groups, I think I would be selling myself short. He should get no less than 1.5 " groups if he has a quality sporter rifle. Even with factory ammo. I would ask no less, or I would sell that rifle.

I have a 22-250 varminter, and I can pretty much count on 3/4" groups. Sometimes a lucky group will surprise me. I can fire half a dozen 5-shot groups and count on an overall average of under 1 MOA. If you discount a lot of the boasting and hot air on this forum, and look at reality, that is a good-shooting varminter.

For a true BR gun, the expectations would be much higher. With a Hart of Shilen barrel, 3/4" at 100 yds would be a great disappointment.

So you see, add "reasonable expectations" to your recipe for accuracy.

If you don't get the results you expect -- or demand -- work on refining your loads.


Pete,
He was shooting off his elbows....
 
Hmmm

A number of years ago, one of the Supreme Court Judges, Potter Stewart, was asked to define 'pornography'. He said he couldn't, but he darn sure knew it when he saw it, (paraphrase).

Maybe the same thing can be said for "accuracy". It is hard to define, but you darned sure know it when you see it:D.........jackie
 
Accuracy and precision is defined by you and you only
Here is a target from my vanguard 270 It is 5 shots at 200 meters This is below avg for this gun but it was all me that made it that way
The heavy lines are 1" and the light vertical lines are 1/2" apart Most of my friends think this is great The guys I competed against wished I would shoot like this because I normally put 10 through a hole smaller than just one bullet hole with the 6ppc and that doesn't get me in mention part of the shoots I use to go to
 

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Mr RBetts, Your audience has mucho experience in these matters. lol Kenny
 
IMO if your putting all your rounds on the paper with a 45/70 at 100 you not in too bad of shape :) its just simply not in the same league of precision as the .270, 45/70's a brush buster
 
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