Am I measuring groups right?

[INShooter]

CTC.. center to center

 

[TAJ45]

BC the holes are smaller, I will deduct .020" from the pill diameter. Just an arbitrary # as an attempt at a more realistic group size. Probably not enough......

 

[MrMajestic]

After reading this thread, I decided to download OnTarget DS version 6.9. Took one of my targets and scanned it in. Directions are scarce but I managed to get it to partially work for me. I could not find a way to print the target along with the data so I just printed both out and cut and pasted it together.

The question is what do all this data mean to me. I am old and don't cotton to new ideas easily.

Looks like you are agg-ing in the .4's Nick. Offsets are just dimensions from center, for sight adjustments. Mean is the radius or 1/2 the diameter of a circle formed by your center to center group. Groups are measured both by minute of angle and inches. Anything else in particular?

 

[Evan]

Another option that's quick and easy is to use an app called Range Buddy. It's free in the google play store, not sure about Apple.

Rangebuddy is what I use. It isn't amazing, but does seem to do an ok job and is quick. It produces stuff like this:

Wish it printed the yardage I've entered into the data tag.

 

[K22]

If you're measuring for competition reasons (or bragging reasons) then the most precise method has to be used that will produce the most accurate center to center group size measurement.

However if you're measuring for load development, as long a you use the same method each time then it really doesn't matter because what you're after is the tightest group by comparison with other loads. A consistent measurement method will accomplish that.

I use the outside to outside measurement and subtract the nominal diameter of the bullet to give me a comparative number to evaluate other load tests. I like this method since its simple and I'm not tying to guess where the center of the bullet hole is which for me is more difficult than finding the outside edge of the bullet hole.

 

[Toby Bradshaw]

Mean is the radius or 1/2 the diameter of a circle formed by your center to center group.

The mean radius is the average distance from the center of the group to the center of each bullet hole. It is a much more useful descriptor of shot dispersion than extreme spread, since the data from each shot is used.

If the mean radius were just half the c-t-c measurement, it wouldn't be any more useful than group size. The mean radius is (almost) always going to be less than half the c-t-c group size, as it is in this case:

c-t-c = 0.41"
mean radius = 0.15"

 

[michaeljp65]

I used to get sick of scanning the target then using a programme to measure the group. Now i use a Neil Jones target measuring tool. So much quicker.

 

[Tim Singleton]

Can one of you explain what the data in my last post is telling me? I am unable to find the definitions for the abbreviations in this program which is why I posted it.

Idk what all those numbers at the bottom mean.
But the targets have a lot of wind in them

 

[Nick Caprinolo]

Looks like you are agg-ing in the .4's Nick. Offsets are just dimensions from center, for sight adjustments. Mean is the radius or 1/2 the diameter of a circle formed by your center to center group. Groups are measured both by minute of angle and inches. Anything else in particular?

This is probably a good program, but there is little in the way of instructions or info on what it all means.

 

[butchlambert]

Rangebuddy is what I use. It isn't amazing, but does seem to do an ok job and is quick. It produces stuff like this:
View attachment 1102549
Wish it printed the yardage I've entered into the data tag.

I'm not seeing anything that coincide with your target. Correct me if I'm seeing it wrong. It appears that your group is 3 bullet holes wide. A .34 group would not be .21 MOA unless you were shooting 150yds.
I am really confused.

 

[MrMajestic]

The mean radius is the average distance from the center of the group to the center of each bullet hole. It is a much more useful descriptor of shot dispersion than extreme spread, since the data from each shot is used.

If the mean radius were just half the c-t-c measurement, it wouldn't be any more useful than group size. The mean radius is (almost) always going to be less than half the c-t-c group size, as it is in this case:

c-t-c = 0.41"
mean radius = 0.15"

you are correct sir, I should have realized when the word "mean" was added it was going to be a statistical evaluation. I guess I need to brush up...

 

[Evan]

I'm not seeing anything that coincide with your target. Correct me if I'm seeing it wrong. It appears that your group is 3 bullet holes wide. A .34 group would not be .21 MOA unless you were shooting 150yds.
I am really confused.

That was my comment, that group is 150 yards but there is no way to tag it as such. There are also 5 shots in that group.

 

[karrarararararar]

That was my comment, that group is 150 yards but there is no way to tag it as such. There are also 5 shots in that group.

Use the icon on the left and it inserts all of your info from your settings

 

[butchlambert]

That was my comment, that group is 150 yards but there is no way to tag it as such. There are also 5 shots in that group.

Evan, I did not say anything about how many shots were in the group. I said the group is 3 bullets wide.

 

[STOMP442]

I downloaded an app a couple of months ago called Ballistic-X. I think it was like $4.99 and works very well. You can add as little or as much info as you like. Here are a couple of examples.

 

[Nature Boy]

I downloaded an app a couple of months ago called Ballistic-X. I think it was like $4.99 and works very well. You can add as little or as much info as you like. Here are a couple of examples.

I have that one too.

I use Ballistics AE for the iPhone to calculate trajectory. It also includes a handy target tool