Measure 3 shot group

[500 Stroker]

When measuring a 3 or 5 shot group at say 100 yards, what is the proper procedure?
Is there a standard in print?

[tyler.woodard04]

Center to center of the farthest two rounds apart is the general rule

[82boy]

Sad thing is there is not exact way of measuring the round, without a dedicated measuring device, and a experienced scorer.
http://bulletin.accurateshooter.com/2013/10/measure-groups-precisely-with-neil-jones-tool/
I use the Sinclair adapter, and thought it is not perfect it is close enough to take to the bank. It needs a high power magnifying glass to accompany it.
http://www.sinclairintl.com/reloading-equipment/measuring-tools/calipers/sinclair-group-measuring-caliper-attachment-prod38778.aspx

The other way targets can be measured is by measuring the outside, to the inside of the furthest holes. You need to go from the black marks. this will get you close, but not on the money. If you shooting one hole groups where there is no inside hole, you can go by the size of the group and subtract the size of the bullet this is probably the least accurate way, but it will get you somewhat close to the ball park. Some folks will measure the size of a single bullet on a target, and use this as the size as the amount to deduct. Still not as accurate as a measuring device.

Out of it all I would not recommend using the bug hole scoring program. I have yet to measure a group with this program that was even remotely close to the actually measured size. (I have tried to measure groups from 100, 200, and 600 yards. I have tried to measure a few hundred groups.) There is too many bugs in this program, and too many opportunities for operator error. Every time I see someone on the net showing off a group shot and measured with this program I laugh. I have seen many groups improperly measured, and to a trained eye, a person can estimate a group size fairly well, and can tell y looking that the persons using these programs are not even in the ball park. A .1 something group can not have any paper showing in-between, but I have seen many groups posted that was measured with this program and look as such. So keep that in mind.

[sharpshooter]

Don't bother to measure 3 shot groups, because it means nothing.

[tiny68]

If you want a simple way to ballpark your groups for the purpose making better reloads, use a dial capiler and measure the largest distance to to the outside of the group and subtract out the diameter of the bullet. I sometimes like to draw a line through the center of the group and measure across that. Problem is that the bullet hole is always smaller than that of the bullet. As long as you stay consistent you can learn what you need to improve groups when optimizing a load.

When I first started shooting Benchrest, my group in matches measured 0.08-0.100 larger than what I have measured with my method.

In terms of the bug hole software, you have to calibrate on a reference to get it to give good results. I have measured 20 plus groups I shot at matches that were officially scored and compared to what I got on bug hole. I typically was within a few thousands. Official targets have exact size boxes that you can use as a reference to calibrate with. That said, I don't find it would the effort anymore.

Luck, Tim

[darkker]

Don't bother to measure 3 shot groups, because it means nothing.
+1
Well said

[Bike Effects]

I use OnTarget PC software.

http://www.ontargetshooting.com/

[500 Stroker]

Don't bother to measure 3 shot groups, because it means nothing.

What do you recommend?

[sharpshooter]

To find the real potential of your rifle, or the load, shoot 10 shots.

[Bike Effects]

I think that 5 shot groups are what the majority of people shoot to compare group sizes, at least in the early stages of load development.

[82boy]

The thing to remember is this is in the "Competition shooting" section.
The old saying is three shoots proves the load, Five shots proves the shooter. As mentioned before if you wish to see the full potential of the rifle then shoot a 10 shot group. I don't know of any competition that shoots 3 shot groups, I could imagine that some club somewhere may do it, but generally speaking no one shoots 3 shot groups for competition. So I would agree measuring three shot groups is a waste.

[sharpshooter]

The industry standard for gun writers is to measure the 2 closest shots center to center, then label the third as a "called flyer".

[chukarmandoo]

The industry standard for gun writers is to measure the 2 closest shots center to center, then label the third as a "called flyer".

That's what I do. My boy gave me some 300 wm that he had loaded because I was complaining about my groups. I shot two shots in the same hole and said that's good enough for me. I'm proud of that to this day.

[RP12]

Don't bother to measure 3 shot groups, because it means nothing.Nothing at all.:rolleyes:

[500 Stroker]

Well, good, bad or ugly us simply folk just use a steel ruler and measure from the center of the two outside holes.
These groups were shot at 100 yards with my new model 11 LRH chambered in 6.5 Creedmoor using out of the box Hornaday 140gr A-MAX ammo.
http://i1367.photobucket.com/albums/r790/Ranchand/65Creedmoor100yd001_zpsf707e7d3.jpg (http://s1367.photobucket.com/user/Ranchand/media/65Creedmoor100yd001_zpsf707e7d3.jpg.html)
http://i1367.photobucket.com/albums/r790/Ranchand/65Creedmoor100yd003_zpsbcca6cb4.jpg (http://s1367.photobucket.com/user/Ranchand/media/65Creedmoor100yd003_zpsbcca6cb4.jpg.html)
http://i1367.photobucket.com/albums/r790/Ranchand/65Creedmoor100yd002_zps5cb1a142.jpg (http://s1367.photobucket.com/user/Ranchand/media/65Creedmoor100yd002_zps5cb1a142.jpg.html)
I also shoot a 1 1/8 group @ 200 yards but failed to save the target.