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Discussion Starter · #1 ·
It seems to me that people have different perspectives regarding a standard grouping.

Groupings to some people can mean the furthest distance between two shots, the average size of where the majority of shots are located, or it could even mean the two closest shots amongst many.

What do you define as a grouping?
 

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For me if I was to take a grouping as you call it,I would fire say 10 shots and draw a circle around the diameter of where they landed. from the centre point(target centre) to the furthest away shot.
The size of said circle would be my grouping.

For example using sgm's with my old 480fps vsr,bench rested indoors at 12m, got a grouping the size a pound coin.could it do that time and time again probably not.
 

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I would take the distance between the two furthest shots.

This would probably be good place to post YOUR groupings here(i'm not happy with my grouping so it would be nice to know how much worst they are than you guys). Just include your guns set up and how you measured the group. Good distance for it would be 15m and 50m. Depends how much space you have.
 

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For me, i consider a grouping to be the total distance between two shots, excluding obvious fliers. I guess that means I get to define what i mean by a fliers, to me a Flier is a singular (maybe 2 depending on number of shots fired) round that increases the size of the grouping by more then 50%.
 

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I do not include the fliers because generally they are due to an imperfection in a BB or a momentary environmental concern, like a strong gust of wind that was not present for the other shots, things other then the rifle itself.
 

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Distance between the center of the holes of the farthest two shots. I normally don't get fliers unless there are is wind or rain or something. I use the center of the shots because that is the average of where the bb hit if that makes sense. School ended my brain is turned off for now.
 

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I fire 10 shots, with all the same variables for each shot, and measure the distance between the two outer shots, but I don't measure from the anomalies that have just been a stray shot from inconsistency in the rifle. E.g. If I had 9 shots within 20cm and then 1 that was 10cm away from the edge of that 20cm grouping, I wouldn't include it.
 

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Discussion Starter · #13 ·
Fascinating! I had a strong feeling a lot of people had their own opinion of a "grouping" and this thread has shed some light :shot:.

Do you guys think there should be a standard? Or is there already a standard that I don't know about? :hehe:

@oderfa
With my current setup that sacrifices power for accuracy (a lot of people don't call their hits here :ashamed:):

15m= 1.25in groupings on avg.
50m= ~4-5in groupings on avg.
Measured from the two furthest shots- including fliers.
 

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The grouping definition I use is the one that benchrest shooters use to score in the events I've attended. I am NOT saying this is a be all, end all rule, but it worked for that group as you work on your shooting technique or work to accurize your reloads (trying to figure out what kind of bullet, gunpowder, brass case, seating depth, OAL etc works best with a particular rifle).

So, how they measured it is: out of a group of five shots, take the longest distance between two, then SUBTRACT the caliber being used. Usual distance

For example, using .223 ammunition-, say you have 2 shots, from outside diameter to other outside diameter is 1". So- 1" - .223 equals 0.777" grouping. In benchrest, they do need to use that level of accuracy as their specialized rifles are very accurate and a match total aggregated score can be decided by a hundredth of an inch.

Using five shots also minimizes luck a little bit (compared to three shots) while keeping costs and barrel wear down (compared to say, 10) which are very real factors with (expensive!) real steel weapons.

So in the end, it's all relative. For airsoft where any hit counts, a 3-4" grouping at 100 feet is probably more than enough for in game accuracy. And for the record, preciion and accuracy are similar- but NOT the same....

More info in case you are interested: http://www.6mmbr.com/index.html

Clearly in airsoft we don't need that level of accuracy- but we can certainly use some of the same principles as we try to make our replicas more accurate.

The important part it would seem to me, is that whatever formula you use and methodology, the only way to know if you are making your replica more accurate is to try and minimize/equalize any factors that are beyond your total control (wind conditions, for example) and being as precise as possible in reproducing your firing of the replica:

-same distance
-same type of BB and if possible, hop up adjustment
-same rest/bipod/stance/shooting technique
-same optics/sights, zeroed consistently
-same EXACT point of aim (I'll explain more about the difference in point of aim and point of impact, as well as an easy trick to minimize waver when shooting at the bull later)

Try to ONLY tweak one factor at a time- be it BB weight, type of barrel or hop up bucking, etc. so you can get predictable results as you experiment.

Just an idea, hope it helps.
Full disclosure, I used to use a Remington 700 SPS in .223 and a Sabre Defence AR-15 in 5.56 for 100 yard benchrest competition. TOTALLY different from airsoft! :D

http://en.wikipedia.org/wiki/Benchrest_shooting
 

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Discussion Starter · #15 ·
Glad to see that method gets the same result I use! The only difference is I measure the closest inner distance between the two furthest shots and add the caliber :hehe:. Same result though :shot:. Usually when I'm collecting grouping data I do a series of a minimum of 10 shots repeated 3-5 times; then I take the average so it's more accurate.

It seems like these forums should have a benchmark standard whenever people mention groupings. Sometimes people mention their grouping, but so many people have their own definition of a grouping that it's difficult to know the actual results.

Great data revenant.Quite informative, thanks for the heads up!
 

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You're welcome, any help I can provide, as the members on this board have already helped me! And sure, using groups of 10 is actually a better way to normalize results- and barrel wear and cost on a BB gun are WAY less than the real steel one! :)

I also assume you measure single shot accuracy, not autofire bursts, right...? Silly question, but had to make sure!
 

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Discussion Starter · #17 ·
I also assume you measure single shot accuracy, not autofire bursts, right...? Silly question, but had to make sure!
Affirmative. Single-shot only :tup:.
 

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Glad to see that method gets the same result I use! The only difference is I measure the closest inner distance between the two furthest shots and add the caliber :hehe:. Same result though :shot:.
Just a thought- say you magically put all ten (or five, or whatever) shots through the same hole. The measured distance of the hole would be (assuming 6mm BBs) 6mm, right? Subtract the caliber (6mm)- equals zero- which would be the best possible result, right?

If you ADD the caliber, the best you can get is a group result of 6mm- even if you shoot them all through the same initial hole!!!

Same result as far as relative accuracy (because we know the baselines), but zero sure sounds cooler...;) Just another suggestion, as in the end the resulting accuracy measurement is just as valid. :tup:
 

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Discussion Starter · #19 ·
Just a thought- say you magically put all ten (or five, or whatever) shots through the same hole. The measured distance of the hole would be (assuming 6mm BBs) 6mm, right? Subtract the caliber (6mm)- equals zero- which would be the best possible result, right?

If you ADD the caliber, the best you can get is a group result of 6mm- even if you shoot them all through the same initial hole!!!

Same result as far as relative accuracy (because we know the baselines), but zero sure sounds cooler...;) Just another suggestion, as in the end the resulting accuracy measurement is just as valid. :tup:
:funny:
That's actually quite funny when I think about it :D

It's quite interesting though, but let's say using my technique that two BB's start approaching each other slowly. When the BB's are extremely close the grouping value can still be easily obtained. The instant the BB's touch, it would be 0mm (distance) + 6mm (caliber). Once the BBs start to overlap, the distance actually become negative if you're still using the same two reference points on the BBs. Once they completely overlap, it becomes -6mm + 6mm and thus the grouping is 0mm.

Same thing, but a lot more conceptual thinking involving negatives. I might as well adopt the outside edges method just in case my groupings overlap (which will be like... never :lmao:.) But just in case, I'll start to use the outer edge method. Good incite :tup:
 
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