How many shots are in a "group"

[moischmoe]

You hear people say, "I shot a 1.25 inch group at 100 yards.) Well, how many shots were in that group. Was the group only 2 shots? 5? What if I shot 10 rounds at 100 yards, and 8 of them were within 1.25 inches, but 2 of them were out to 3 inches. I now have a 3 inch group.

What I'm trying to say is, the more rounds you shoot, the bigger your group is going to get.

My question is: Is there a standard for how many rounds are in a group?

 

[42769vette]

usually when you hear that its a 3 shot group. i usto do 3 shot groups but now do 5 or more in eachgroup. but to answer your question there is no standard. could be anywhere from 3 to 20.

also there is no standard as far as measuring the group. some do ctc (center to center) some do edge to edge,

 

[smoking357]

The occasional shooter is content with three.

A competitor needs a minimum of five shots.

 

[aclark]

A lot of people shoot 3 shot groups, however, it has been discussed (i think on SC), that this is not statistically significant because your sample size is too small. The post went on to say that a measured group should be AT LEAST 5 shots to have any significance. I try to do 5 shot groups whenever I can.

As for measurement, you can either measure center to center, and then that is your group size. Or you can measure edge to edge and subtract the bullet dia. to get your group size.

 

[dr632]

This reminds me of Dr. Herb Bailey in my Calc I course ... he told us a story about a debate between a mathematician and an engineer. The debate was a problem that could be approached from a practical application context or a theoretical context.

The question: If you were across the room from a smoking hot naked lady, and with each step you halved the distance between yourself and her, would you ever reach this lady? The mathematician's response was "No" as you can always theoretically find half the distance ... of course, the engineer's response was "perhaps, but I'll be close enough with just a few steps".

Now that Rose-Hulman is coed, they can't share these types of Life Skill lessons anymore, but the theme of this story is valid with your question.

Ammunition is/can be quite expensive. So, one should shoot groups to evaluate the Cpk (a six sigma term) of the weapon system - the capability of the weapon - and then center that capability about a known zero. I try to eliminate all contributions sources of error from this calibration exercise.

Since my 460 Weatherby Mag is $6-7 a round .AND. rough on the recoil, I try to (1) use smaller numbers of rounds, and (2) use a lead sled so that I'm am out of the equation. Defining the capability of the specific system is important to know, when the weapon is in the field and you are in pursuit of your game ... or purpose if not hunting. With my semi auto's in the .223 range, I use a larger number of rounds to establish the Cpk of the rifle.

Interesting question on how the diameter of the group is measured. I guess if you are a bulls eye shooter, if you cut the inner ring it counts - so that implies the smallest diameter circle that intersects or includes all of your group bullet holes defines the group radius/diameter. The circles I run in (no pun intended) approximate a circle that contains all the bullet holes ... as if one had a draftsman circle template of various diameters you could overlay on the target to enclose all the holes that make up the group.

Sorry for the long post - good points to clarify.

 

[WhitleyStu]

I consider a "group" to be a full mag or cylinder. For sight in purposes 3-5 rnds.

 

[furbymac]

i usually do 1 shot groups it makes me feel better

 

[Colt556]

For high power rifle I shoot 3 shot grps, sometimes 5. For rimfire I shoot 5-10 shot groups. Handguns I normally shoot 5 shot groups. These are for measurement. Any other time I shoot until the target is of no use anymore!

 

[ROLEXrifleman]

as stated above

3 = is the old norm

5 = current standard

10 = when you want to show off

 

[Boilers]

 

[DeadeyeChrista'sdad]

In my five shot groups, usually it's the three that are on the paper.

 

[rockydog]

I read a lot of gun reviews and they always seem to be 3 shots or 5 (I shoot 5 for my own) I think 3 shots are acceptable and even 3 shots can be amazing, and of course maintaining that accuracy for 2 more shots is harder and probably more accurately shows the ability of the gun.

 

[42769vette]

there have been alot of times after the 3rd shot ive said "that counts i dont want to screw this target up" i always end up shooting the other 2 and usually end up screwing up a beautiful piece of paper

 

[JCA1776]

i usually do 1 shot groups it makes me feel better

That's my kind of group!

 

[Jack Ryan]

You hear people say, "I shot a 1.25 inch group at 100 yards.) Well, how many shots were in that group. Was the group only 2 shots? 5? What if I shot 10 rounds at 100 yards, and 8 of them were within 1.25 inches, but 2 of them were out to 3 inches. I now have a 3 inch group.

What I'm trying to say is, the more rounds you shoot, the bigger your group is going to get.

My question is: Is there a standard for how many rounds are in a group?

What difference does it make? I don't believe ANYTHING I didn't see them shoot with my own eyes.

 

[42769vette]

What difference does it make? I don't believe ANYTHING I didn't see them shoot with my own eyes.

very true. by reading internet forums you would think every rifle ever made is sub moa with factory ammo

 

[bglaze]

more than 1

 

[Jack Ryan]

very true. by reading internet forums you would think every rifle ever made is sub moa with factory ammo

When they write the ad it does.

Later when you show up with the money and all they have to do is put three in a row in the bull all of a sudden it was different amo, the wind wasn't blowing, they had a different scope on it, they don't have any sand bags...

When they start making their excuses walking to the shooting bench I just stop, turn around and leave any more. Last time the kid wasted half my day driving to pick up a rifle at at his advertised asking price and he shot half a box of shells before he hit the paper at 50 yards.

 

[dleeharrison]

In my Army firearms training, a shot group was three rounds. I was trained to fire three rounds as a group back in the early 60's by my father who was an expert rifleman in the army.

 

[Seancass]

What I'm trying to say is, the more rounds you shoot, the bigger your group is going to get.

If your group keeps getting bigger, then you still arn't representing your accuracy with that firearm.

I think if you're sighting in the firearm, then 3 shots is good enough to move your point of aim around.

However, if you want to be bragging about accuracy, 10 shots is the minimum.

There's been huge discussions on this, but a 10 shot group is just the sum of 3, 3 shot groups(+1). Had you shot them all on different targets, they may look like great groups, or maybe one would have a "flyer". However, when you stack them on top of each other (in a 10 shot group), it seems like your group has "opened up". In reality, you are just more accurately representing the performance of the firearm.

I usually shoot 5 shot groups.