Group Size

Para D

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Apologies if this has been done before but a quick search did not reveal an answer to my question and life is only so long to be going through countless pages of threads.

I am new here and still trying to figure out what is kosher so if this is the wrong forum please let me know and I will ask to move/delete it.

I was testing out some factory ammo today 168 v 175 grain from a rem 700 @100m. Been slowly getting into long range shooting and my reading has not revealed an answer to this question. Pictured below are two groups I shot. On both there is an obvious "flyer" but I would not have called it at the bench which I think means it would count in a competition if I am not mistaken. Outside of competitions though would you, personally, include the flyer as part of your group for your own stats or would you measure the group best 4/5. I'm not asking to pad my ego and claim I have a better group than what I do it is more about stats. In science at university we would automatically remove any outlier that is within 2 standard deviations from the rest of the data set. Is that something that is typically done in shooting? Just want to be speaking the same language as everyone else essentially.

Thank you for your replies.
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I'm not an expert but I have always considered all 5 shots to 'count' in my review of group sizes, to me the point is can you shoot 5 in a row in one hole or not. I consider a 'flyer' my fault due to lack of focus.
 
Since you understand math.. the best answer is INCREASE YOUR SAMPLE SIZE

Shoot some more 5rds groups under good conditions, no rushing... just shoot your best. Then average your groups over say 5X5rds and see what happens

Many shooters like to do the 4/5 rds for their accuracy cause it typically makes for better accuracy but that fifth shot went where it went for a reason... and the test is to confirm what is the actual average group size. Once that is confirmed, steps can be made to remedy and a better comparison of before/after can be done.

You may find that the flyer is actually part of the overall average when the sample size is increased...

Jerry
 
I count most of them. Good example was tonight. I went shooting with my buddy. I had a awesome group going, about to shot my forth shot and he pulled the trigger a millisecond before I did. I flinched and lost the group. So I “tossed” that shot and shot 2 more to make up. But if nothing out of the ordinary happen and still got a bad shot I try and figure out what happen. At the end of the day there are tons of reason why that flyer could of happened. You obviously are doing something right to put 4 in one ragged hole. Don’t sweat it, more trigger time and you’ll know a good shot from a bad before you even see the hole on the paper.
 
Thats, some pretty nice shooting. I like to count my flyers so that I can improve my shooting, but to each their own.
 
Thank you everyone. Agree with what everyone has said especially bigger sample sizes. Just tricky cause more data equals more money LOL. Guess I shouldn't preach about ammo costs to the choir.
 
In PRS, every shot you fire during a match counts for score. It should in any sport that is supposed to be tactical oriented IMO, even on a gallery range.

If you want to evaluate accuracy for LR, shoot 10 shots at 300. If you want to do multiple groups of less shots, then you need to superimpose them.

Meh... this one's not so great...
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Nice group!
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Another nice one! Yes!
threeshot02.jpg

Uhm... no, not really!

What the true representation of the rifle's capability is:
threeshot04.jpg

Group size is not paramount when you don't have sighter shots. Consistent velicity and consistant POI are more important. A wondering zero will tank you.
 

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In PRS, every shot you fire during a match counts for score. It should in any sport that is supposed to be tactical oriented IMO, even on a gallery range.

If you want to evaluate accuracy for LR, shoot 10 shots at 300. If you want to do multiple groups of less shots, then you need to superimpose them.

Meh... this one's not so great...
View attachment 183004

Nice group!
View attachment 183002

Another nice one! Yes!
View attachment 183003

Uhm... no, not really!

What the true representation of the rifle's capability is:


Group size is not paramount when you don't have sighter shots. Consistent velicity and consistant POI are more important. A wondering zero will tank you.

Wow thank you for taking the time on that
 
In PRS, every shot you fire during a match counts for score. It should in any sport that is supposed to be tactical oriented IMO, even on a gallery range.

If you want to evaluate accuracy for LR, shoot 10 shots at 300. If you want to do multiple groups of less shots, then you need to superimpose them.

Meh... this one's not so great...
View attachment 183004

Nice group!
View attachment 183002

Another nice one! Yes!
View attachment 183003

Uhm... no, not really!

What the true representation of the rifle's capability is:
View attachment 183005

Group size is not paramount when you don't have sighter shots. Consistent velocity and consistent POI are more important. A wandering zero will tank you.

Yes. In some target sports we get a couple sighters and can adjust the sights before going on score. In some events we can't.

Your rifle needs to group well, but also has to group to the same place, each time. This is why good bedding is so important. It helps both grouping and consistency. And you have to make sure you don't get solvent leaking in to the bedding and make sure the action screw torque is always the same.

All shots count, unless you know you did it yourself. And 5 shot groups don't mean much. We don't shoot 5 shot matches. A poorly heat treated barrel will warp as it warms.

Let's say a given set up tends to throw 1 in 10. A flyer could have been the shot that would have been on the left edge of the group but it goes farther out. An obvious flyer. But the same shot could have gone right - into the group. Now the same flyer is masked.

We kid ourselves looking at 5 shot groups. I shoot a minimum of 10, and often see the first 5 shots look outstanding, but by the time I shoot #10, it is a ho-hum group.

I prefer 20 shot groups, so I know the group means something.

I shoot a lot of groups. On my home range I fill garbage cans with brass. A typical session is 200 rounds. I have a fan to blow the heat waves off the barrel.
 
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If you want to feel good, shoot 3 round groups.
If you want t true metric, and to really challenge yourself. The bigger the group the better. Its exactly like Mystic and kombayotch said, IMO
 
In PRS, every shot you fire during a match counts for score. It should in any sport that is supposed to be tactical oriented IMO, even on a gallery range.

If you want to evaluate accuracy for LR, shoot 10 shots at 300. If you want to do multiple groups of less shots, then you need to superimpose them.

Meh... this one's not so great...
View attachment 183004

Nice group!
View attachment 183002

Another nice one! Yes!
View attachment 183003

Uhm... no, not really!

What the true representation of the rifle's capability is:
View attachment 183005

Group size is not paramount when you don't have sighter shots. Consistent velicity and consistant POI are more important. A wondering zero will tank you.

Kool pics... let's play the what if game... Let's assume these are actual groups AND conditions were light and POA was the same.

The first group (yellow dots) is quite open... that tells me the cold bore condition of the barrel is not good. maybe the barrel is too clean... or too dirty from a cold bore. Or the shooter needs to get in the game a whole lot faster.

The next group (black dots) has excellent accuracy but the POI is low. If the shots were well made, then the barrel is definitely settling down low vs cold.. something to note in your log book cause elevation in this case is barrel NOT condition related.

Now the final group (red dots) is both similarly accurate AND precise. If a scope/sight adjustment was not made, I would suggest that the shooters position was better with a more solid follow through and that can easily raise your POI. If the shooter feels that the black and red group were equally well made, I would suggest that the barrel has a temp related issue and further testing would be done to confirm the situation.

When I look at my shots, I chart where every shot landed and then relate it to me, the conditions, and the rifle. Group tuning is a system and you have to include the "why" in all parts... Location of the group is just as important as how big it is.

What a larger sample size can help you determine is whether you as a shooter is fading later in the string. A change in body position will cause the shot to go out. Cheek pressure, parallax, etc so never discount that the rifle and load may be fine but the driver is at fault.

The goal is for the groups to be similar in size AND location... that indicates that the system is stable and repeatable. This is a system that can make hits at LR even though the pure accuracy is a bit big.

Something that goes big - small - somewhere in between - never the same place twice, needs to be fixed cause you have no idea where that next shot is going to go.

Has been said many times before... there are plenty of 1/2 MOA rifles, not so many 1/2 MOA shooters.

Jerry
 
Has been said many times before... there are plenty of 1/2 MOA rifles, not so many 1/2 MOA shooters.

Jerry

A lot of good ideas and thoughts there and I appreciate your's, and everyone else's, feedback. I don't want to be a pedant here, seriously just seeking understanding. Following what you said then, if we had a "universal language" in long range shooting, what would the criteria be to be considered a sub-minute group/shooter?

There have been a few different perspectives on this thread so far: 3 vs 5 vs 10 vs 20 round groups. I know the terminology is not as important as say knowing what your ability is and the characteristics of the gun, but stepping away from bragging rights, when a company claims they are selling a sub minute gun or you want to take part in a training course with someone who doesn't have immediate name recognition, and they claim they are a sub minute shooter, what, if any, is the exact definition?

Is it a 3 or 5 round group? IS there a consistency element?
 
You pose a very important question and one the industry is reluctant to really address. There is no real standard so alot is left to opinion and interpretation and caveats.

Gets a wee bit confusing and frustrating.. I get that.... so you will need to form your own parameters and see how the gear and training you want fits into it.

Then there is the matter of skill from the end user... and thus my statement. So the best gear in the world is still limited by the skill of and application of the end user.

For me, my paradigm is competition. Can't really kid a target at 1000yds. You either have the set up to hit it or you don't. My sport has been F class and the course of fire requires the very best in your set up and shooter. Those that compete and do well at the top levels, understand how hard it is and focus on the steps and gear that matter.

Choose the gear that fits your end use goals and performs the tasks as needed. Needs vary widely so as long as the end results gets the job done, it's all good.

Jerry
 
A lot of good ideas and thoughts there and I appreciate your's, and everyone else's, feedback. I don't want to be a pedant here, seriously just seeking understanding. Following what you said then, if we had a "universal language" in long range shooting, what would the criteria be to be considered a sub-minute group/shooter?

There have been a few different perspectives on this thread so far: 3 vs 5 vs 10 vs 20 round groups. I know the terminology is not as important as say knowing what your ability is and the characteristics of the gun, but stepping away from bragging rights, when a company claims they are selling a sub minute gun or you want to take part in a training course with someone who doesn't have immediate name recognition, and they claim they are a sub minute shooter, what, if any, is the exact definition?

Is it a 3 or 5 round group? IS there a consistency element?

Since you posted in the Practical Precision Forum, you are for the most part shooting at +1 moa targets (usually 2moa) and scoring is all hit or miss. There are never sighters, and you may have 10 mils dialed on for a stage, and back to zero the next.

With that, you need to deal with the ammo/gun/optic/shooter as a whole, and not fuss about absolute mechanical accuracy of the gun itself.

80% of your targets are 300-750 yards and SD is not nearly as important as people like to think, and neither is group size.

Do a ten round OCW, play with seating depth to get 0.5-0.75 moa groups, and then prove your whole system by shooting a 3 round group cold bore with the scope returned to zero every time you go to the range.

Shoot a quick tall target test often as a prone fundamentals exercise whenever you can, then return the scope to zero and shoot another 3 shot group with a warm barrel.

Shoot every group from the prone off a bipod out of the magazine.

If you can overlay several of these cold bore groups and be under 1 moa, your rifle/ammo/scope will be capable of winning any prs match in the country.
 
Since you posted in the Practical Precision Forum, you are for the most part shooting at +1 moa targets (usually 2moa) and scoring is all hit or miss. There are never sighters, and you may have 10 mils dialed on for a stage, and back to zero the next.

With that, you need to deal with the ammo/gun/optic/shooter as a whole, and not fuss about absolute mechanical accuracy of the gun itself.

80% of your targets are 300-750 yards and SD is not nearly as important as people like to think, and neither is group size.

Do a ten round OCW, play with seating depth to get 0.5-0.75 moa groups, and then prove your whole system by shooting a 3 round group cold bore with the scope returned to zero every time you go to the range.

Shoot a quick tall target test often as a prone fundamentals exercise whenever you can, then return the scope to zero and shoot another 3 shot group with a warm barrel.

Shoot every group from the prone off a bipod out of the magazine.

If you can overlay several of these cold bore groups and be under 1 moa, your rifle/ammo/scope will be capable of winning any prs match in the country.

Thank you, this is awesome.
 
Since you posted in the Practical Precision Forum, you are for the most part shooting at +1 moa targets (usually 2moa) and scoring is all hit or miss. There are never sighters, and you may have 10 mils dialed on for a stage, and back to zero the next.

With that, you need to deal with the ammo/gun/optic/shooter as a whole, and not fuss about absolute mechanical accuracy of the gun itself.

80% of your targets are 300-750 yards and SD is not nearly as important as people like to think, and neither is group size.

Do a ten round OCW, play with seating depth to get 0.5-0.75 moa groups, and then prove your whole system by shooting a 3 round group cold bore with the scope returned to zero every time you go to the range.

Shoot a quick tall target test often as a prone fundamentals exercise whenever you can, then return the scope to zero and shoot another 3 shot group with a warm barrel.

Shoot every group from the prone off a bipod out of the magazine.

If you can overlay several of these cold bore groups and be under 1 moa, your rifle/ammo/scope will be capable of winning any prs match in the country.

Have to agree with this more or less. I know when I started shooting (and still do sometimes) I get all tied up in group sizes but really they are not all that important for PRS type shooting.

A top shooter with a 1MOA gun would probably shoot the same score as with a .25MOA gun.
 
A lot of good ideas and thoughts there and I appreciate your's, and everyone else's, feedback. I don't want to be a pedant here, seriously just seeking understanding. Following what you said then, if we had a "universal language" in long range shooting, what would the criteria be to be considered a sub-minute group/shooter?

There have been a few different perspectives on this thread so far: 3 vs 5 vs 10 vs 20 round groups. I know the terminology is not as important as say knowing what your ability is and the characteristics of the gun, but stepping away from bragging rights, when a company claims they are selling a sub minute gun or you want to take part in a training course with someone who doesn't have immediate name recognition, and they claim they are a sub minute shooter, what, if any, is the exact definition?

Is it a 3 or 5 round group? IS there a consistency element?

This is an old issue. In 1980 Creighton Audette presented a paper commenting on group size.

he said a 5 shot group would be 1.23 larger than a 3 shot group. And a 10 shot group would be 1.53 larger than a 3 shot group. And a 20 shot group would be 1.79 larger than a 3 shot group.

So, if you shoot a 3 shot group (and with a light hunting barrel, that might be all you can do) double it and you will be about right for knowing what the rifle can do.

Creighton was a leader in the area of rifle and ammo development and no shrinking violet when it came to debunking pet theories. he considered a single 10 shot group of little value and was contemptuous of anything less.

http://m14forum.com/accuracy/178649-excerpts-creighton-audette-article-group-size-probability.html
 
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