Just a quick yes/no if this is how you measure groups...

V

VaniB

New member
Heck....I'm gettin tired of of the rudimentary method of trying to use a ruler to measure group size.

DO I UNDERSTAND THIS TO BE THE CORRECT WAY TO MEASURE GROUPS: I put my caliper up against the two most opposite bullet hole edges in my 5 shot group, taking a measurement of the two furthest most outside points in the group, and then subtract the bullet diameter?

For example....if it was five shots fired from a .204 Ruger..... I would proceed by using my caliper to measure the group from the outside edge of one bullet hole to the furthest most outside edge of another bullet hole, if for example that measurement was .445", I would then subtract .204" from .445" to get a formal group size of .241"
(which is the proper center- to- center manner with which groups are measured...right?)

Correct?
 
If you don't have a caliper attachment, and I am not sure that one is avaliable that covers .20 caliber, you will get a more accurate result if you measure a single bullet hole and subtract that rather than the bullet diameter.
 
Internet groups are usually measured by subtracting the caliber (.204)
As Boyd suggested the one bullet hole measurement is more accurate. .186 last time I measured one in typing paper which is my unofficial target of choice.

It all becomes much easier if you shoot larger groups. You just measure outside to inside.:D I usually choose this method:eek:
 
Set your digital caliper at .204 and reset it to zero. That way you won't have to subtract. I wouldn't get too anal about measuring your own groups. A few thou difference here and there won't matter and all you are really doing is comparing group sizes for load development, right? Even world records are measured by committee because no two people will arrive at the same number.

Ray
 
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Hmmm....Thanks for opening my eyes. I see that a simple closed "Yes/No" answer does not apply to the parameters I set.

As I do not participate in formal competition, I have no clue what you guys are referring to as a caliper "attachment", what it looks like, or how it works. It makes sence and doesn't surprise me now to learn that there are such devices.

But more importantly.....thank you for bringing it to my attention that the actual holes in my target do not measure a .204" diameter. Yes, they are more of a .190" I never actually measured the size of the bullet hole itself until now to discover that it's not even close to .204 size.

It is of my desire that when I post or display my group sizes to folks, that I be honest and ACCURATE with the size of the group I'm reporting. For example, I'd much rather be off a bit and report a group being .413" in size when it is probably actually a smaller .403" sized group.......rather then the other way around and take undue credit that I don't desrve.

This is a precision sport, and feel that BS and misrepresentation is out of place here. (...a reason why I also never pay any mind to those people who display 3-shot groups.)

Thanks for the input.

EDIT: cheechako...I was posting at the same time you were. Thank you too for your input.
 
What About Fliers?

Sorry to hi-jack your thread but this just came up.

I was shooting my .308 yesterday with the wind howling and had 4 shots cutting a hole and then a @#$% flier about 1/2" low. :mad: Then shot number 6 went into the same hole as the initial 4.

Question: Do some measurements throw out the flier or average it in? My next purchase will be wind flags. Thank you in advance!
 
In group competition ALL shots on the record target count.

You could have 4 in 0.05 and one shot out an inch and you have a 1.05 group.

You could even have 5 in 0.05 and mistakenly fire a 6th shot and put it out an inch and still have a record 1.05 group !
 
Talon.........

..in BR Shooting ALL shots count, no Mulligan or OOPS allowed. We shoot either five or ten shot groups(Unlimited). The groups are measured after each match of 5/10 shots groups. The 5 groups are added together and averaged out for the 100 yard agg. ( 5 groups = X divided by 5 = aggregate. At 200 and 300 hundred yards, groups are measured and reduced to MOA and averaged in with the 100 yard groups for a grand aggregate.
 
Talon1959 said:
. . .I was shooting my .308 yesterday with the wind howling and had 4 shots cutting a hole and then a @#$% flier about 1/2" low. :mad: Then shot number 6 went into the same hole as the initial 4.

Question: Do some measurements throw out the flier or average it in? My next purchase will be wind flags. Thank you in advance!
Click to expand...

Talon

I ALWAYS throw out fliers when measuring my groups. After all, it wasn't my fault.:D;);)

In fact, I will do ANYTHING to make my groups smaller than they actually were. Including lying.

Ray
 
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Thanks!

LOL!

My rifle shoots really well, I just had a brain fart. I was just amazed that I was cutting out a hole with the wind as bad as it was. I needed an excuse to play with my new Rock BR, wind or no wind. I got the newbie disease bad!

I am used to the "you shot it, you bought it" scenerio as I shot competitive skeet for a long time. Nothing like missing the 100th target for a 99 and you're going home early. LOL!
 
If you have a scanner or digital camera you could try the program I've been developing that's used to measure groups. It's not certified but it will be within a few thousandths if you scan at 200 dpi or better. Should be good enough for load development.

You can save the targets off into a file for later reference and save a graphic of the target with the group information embedded for posting on the web. Take a look at: www.ontargetcalc.com. I'm still working on the program but it's pretty stable and should work quite well.

If you give it a try let me know if it helps. You can send a message through the webmaster email link on the website.

Jeff59
 
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