Definition of “groups”??

[Sanch]

Dumb question maybe but I’m not sure after reading through the 25 yard thread. How do you define groups? What rounds are included in the grouping of shots?

I always though it was the rounds you fired in one string, because you have certain grip, you’re really not changing your grip between shots. And most important, if you have a bad grip then the gun shifts after after shot and by the 4th or 5th shot in tha string you find the gun isn’t in the start position anymore so looking at the rounds from that string in that definition let’s you see if the group is moving left or up or whatever as your grip shifted mid string.

Okay so that’s what I thought then I read people saying with 25 yard slow fire they relax your arms close your eyes take a deep breath for 20 to 30 seconds and then come back up to target. So suppose you did that with 10 rounds over the course of I guess 4 to 5 minutes. Is that one group? By what I thought group meant, then you’d really have no group In this case because each shot was a completely different presentation and different grip.

If the definition was real loose goosey then could we say every single round you fired in the entire range trip at the Target fixed in one distance is one big group even though you changed mags a dozen times?

When it comes to zeroing a gun I know the purpose of the group is to find the middle and then make adjustments Based on that because if you only took one shot and try to adjust on that maybe you threw that shot. I’m this example of a “group” I guess it doesn’t matter if you eat a samdwhich or smoke a cigarette between each round fired of the 3 round “group” because you’re just trying to validate where the sights are.

So I’m just really confused. Is there a definition of group? Does it differ based on what you’re using it for? Like I said with zero a rifle, then it doesn’t matter how much time between shots or whether you put the gun down because the purpose is to find where the sights are hittin. But I’m my mind with pistol, a group would be limited to a string of fire from a single presentation without reloading or without changing grip because the purpose is to validate my consistency of the shooting physiology I created in my grip stance sight picture etc.

Bonus question - how many rounds should a group be to be considered valid? I would say 3 to 10, because any less than 3 and if one round is a fluke then at least half the rounds are flukes (1 out of 2! Or 1 out of 1!) and it doesn’t mean much. But more than 10 and I wonder why did I need to hold my stand grip etc consistent to shoot the same twrget in the same spot more than 10 times? Personally I’ve been working with 4 lately on my strings because 3 isn’t quite enough time to see the grip change from recoil, if the gun shifts grip slightly each round due to recoil and poor grip then it gets cumulative over time and I’m not sure 3 round string is enough to see it. But I haven’t gone to 5 or 6 for the most part because of $$$. Though I do sometimes toss a 6 round Billy in there to check grip over a longer string and to appease the Ayoob gods LOL

Also my problem with Just using 3 round string for my 25 yd is sometimes I throw one and if I shoot 4 and throw one then I see a nice tight 3 round group and a little guy that no one should worry about, 6 inches away. Like I jerked that round or something. Now suppose I do only a 3 round string and I throw one then I don’t really know if I threw one or just had a crap huge group because the two remaining rounds aren’t enough to prove a nice group to me.

Then again if I’m odium precision warm up work at 3 yards then a 3 round group seems fine because I’m not as likely to throw them 6 inches off and if I do see 2 shots in the same hole and one shot 6 inches off I know that third one is a throw for sure. But at 25 if I nail two and throw one, it just looks like a crazy big wild group usually. So maybe the answer is that you need more rounds to make a valid group at longer distances or with greater speed since both make you more likely to throw.

Those are my thoughts but man everyone here is so much smarter than me so I want to hear other opinions or if there’s any industry standard definition. I post my opinions not to say they are right but just to spark discussion so you guys can tell me specifically what’s wrong about my ideas!!

[RJ]

I would define a "group" as follows:

"The diameter of the smallest circle covering the point of impact of three or more shots, attempted using the same weapon, ammunition, distance, and aiming technique."

PS I'm just some random .civ dude on the internet trying to stay off YouTube.

[Darth_Uno]

A group is just a measurement of consistency. It shows how repeatable the performance is of both yourself, and your weapon.

We’ve all seen and had “lucky” shots, so 2-3 rounds isn’t quite enough to gauge consistency. 5+ eliminates any “lucky” shots and is a much better indicator.

In a shotgun class, we fired slugs at 25 yds. My first two were about a foot low, but touching. My third was dead center bullseye. That’s a 3 round “group” but not enough info to tell me anything useful.

JMO. @RJ, If I’m ever on YouTube, it’ll be on a Gun Blooper video.

[AGR416]

I think you are overthinking it.

A group is the number of shots fired in a single string. There is, however, no time limit to shoot a group, so it is perfectly fine to lower the gun, rest your eyes and get back up on target.
Talking about shooting 1 round and then resting while smoking a cigarette, or having a snack or whatever, in between rounds is a unrealistic example, as no one does that.

The more rounds in a group, the better feedback you get regarding you ability to consistently shoot the firearm.

For verifying zero with a handgun at 25, I shoot 5 rounds. For a rifle it will depend, but 5 or 10 rounds is my preferred.

Remember that group shooting has two purposes;

1. Measure precision, ie the size of the group
1. Measure accuracy, ie having the MPI impact the correct spot on the target

[Dave T]

To me there are two different kinds of "groups". One is to test the gun or ammunition's consistency. This would probably be slow fired, often from a rest, at least 5 shots, and maybe more. And, I think it needs to be at a minimum of 15 yards. 20 or 25 would be better, and more informative.

You might also shoot a group to determine your practical accuracy. I'd fire this standing with no support, and I'd test both strong hand and free-style (supported) shooting. When doing this I fire two from the holster then go to ready. I'll fire another pair from ready, and probably repeat that drill until the gun is empty. As above the longer the distance the more it will tell you.

YMMV,
Dave

[Duelist]

I think you are overthinking it.

A group is the number of shots fired in a single string. There is, however, no time limit to shoot a group, so it is perfectly fine to lower the gun, rest your eyes and get back up on target.
Talking about shooting 1 round and then resting while smoking a cigarette, or having a snack or whatever, in between rounds is a unrealistic example, as no one does that.

The more rounds in a group, the better feedback you get regarding you ability to consistently shoot the firearm.

For verifying zero with a handgun at 25, I shoot 5 rounds. For a rifle it will depend, but 5 or 10 rounds is my preferred.

Remember that group shooting has two purposes;

1. Measure precision, ie the size of the group
1. Measure accuracy, ie having the MPI impact the correct spot on the target

I agree with most of what you said, but people shooting rifles who want to see repeatability of shots with with cold bores will rest a significantly longer period of time between shots than most other situations. Not an every-day kind of thing, but when testing a new rifle or new load in a rifle, I definitely do that.

[Alpha Sierra]

I think you are overthinking it.

Seems like a reoccurring theme

[Gio]

I think the OP's question has been answered, but to share my own thought process and procedures for shooting groups and the reasons why, see below:

If I am trying to measure the accuracy capability AND sight in a pistol to make adjustments to my point of impact relative to my point of aim, and I do not use a ransom rest, I generally will fire a rested/supported group with my hands on a sandbag and seated at a bench at 25 yards. I will fire between 3-5 rounds and repeat this for several reps or groups in a row, marking and photographing each individual 3-5 shot group. I find if most shooters attempt to fire more than 5, fatigue will set in and cause them to induce excess variation in the group size. If I use a ransom rest, I fire a 10 shot group. The size of this ransom rest 10 shot group seems to correspond to the average of my 3-5 shot rested groups. One key to minimizing shooter induced variations in a rested group is to never readjust your eye focus or grip throughout the firing of the group. I.e. never look down range at your target to see the point of impact in between shots.

If I'm just working on slow fire accuracy fundamentals and attempting to fire a bullseye course (which is required for me to maintain a certification level), I will pull the gun down and sometimes reholster it to rest my hands and eyes throughout the 10 shot, 25 yard string. My target is a 3" diameter 10 ring though, where as the accuracy capability of a stock gen5 Glock is around 1.5-2". I am resting to minimize the chances of an extreme outlier such as a 7 or 8 ring hit caused by fatigue, and give myself the best chance of keeping rounds inside the 10 ring. Comparing the rested group size above to a standing unsupported bullseye group size is a good way to measure how much shooter induced variation there is.

Another interesting observation: For me and my capabilities, I find that a 15 yard standing unsupported 5 shot group correlates pretty close to the same size as a sand bag/bench rested 25 yard group.

[JSGlock34]

Another interesting observation: For me and my capabilities, I find that a 15 yard standing unsupported 5 shot group correlates pretty close to the same size as a sand bag/bench rested 25 yard group.

Your capabilities are truly next level, but I find this true for me as well. I suspect in my case that eye sight is a detrimental factor at 25 yards and holds me back regardless of the additional support of the rest.

[mmc45414]

Is there a definition of group?

I would define a "group" as follows:
"The diameter of the smallest circle covering the point of impact

More rifle stuff, but it is my understanding that in competitions like bench rest where group size is the score the diameter of the bullet (radius on both sides) are deducted so a smaller caliber gains no advantage.

Also the X-Y dimensions can be another data point, my F-class (1000yd) buddy explains that group height is an indication of your skill at the reloading bench and the width of the group is an indication of the accuracy of your (or the coach's) wind calls. Obviously there are many factors, but if your shots look like a waterline going thorough the X-ring you probably have a good rifle and a good powder scale.