measuring groups

NShunter1254

NShunter1254

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Nova Scotia Canada
Can someone explain in layman's terms the standard method of measuring groups.I always measure the outside distance of the two farthest apart but after reading some other posts, I believe this may not be the correct way.
 
If you are measuring group max dispersion as in "I just shot a 0.25" group" then it is hole center-to-center distance between the two most distant holes. If scoring a target then it is the position of closest side of each hole to the center of the bullseye.
 
If just shooting groups, you want the distance of the two farthest apart holes, minus the diameter of one hole (or the average diameter of the "sighters"), to give a center-to-center measurement.

It is somewhat common practice to overlook a flyer, if you caused it, not the rifle of the ammo. This only applies when you are testing the accuracy of the gun and/or ammo.

If shooting targets as a measure of skill, you measurement includes all shots taken.

There is a program out there somewhere that measures and calculates your shot targets and give all sorts of information.

There are many varieties of targets and challenges that are scored differently.
 
So if i understand correctly the group below measured .473 outside to outside when in fact i should subtract .220 which is the bullet size which would make the actual group size .253 .



IMG_0442.jpg
 
Yes that is correct athough you should deduct .223 as a 22 rimfire bullet measures
.223" . .473 - .223 = .250 good shooting :) .it will be extremely good shooting if you can repeat that at 50yds :D .What club do you shoot at ?
 
Measure some of the holes to get the amount to subtract from your outside measurement, a .22 bullet doesn't usually leave a .223" hole in the paper. Sighters are good for this if you use them, as Jahred.F mentioned. I usually try to measure grease rings instead of the edge of the hole, I find them more consistent than the hole edge.


Mark
 
Scan your target and use On-Target software. It'll do all the calculation work for you!

ht tp://www.6mmbr.com/ontargetsoftware.html
ht tp://www.ontargetshooting.com/index.html

It's a freeware download and works awesome!
 
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