Technical Find or ask for all the information on setting up, tuning, and shooting your bow. If it's the technical side of archery, you'll find it here.

Measuring Groups

Old 09-21-2005, 06:01 PM
  #1  
Thread Starter
 
Join Date: Sep 2005
Posts: 1
Default Measuring Groups

I have to test accuracy of different arrows for a school project. I am going to shoot a 3 shot group at my target, but how can i measure the groups?
TikkaBowHntr is offline  
Old 09-21-2005, 06:20 PM
  #2  
 
Join Date: Feb 2003
Location: Blissfield MI USA
Posts: 5,293
Default RE: Measuring Groups

with a gun you normally measure the outside of the group and then subtract the diameter of one bullet hole. With arrows I normally just measure the longest distance between arrows on the outside.

Paul
Paul L Mohr is offline  
Old 09-21-2005, 06:38 PM
  #3  
 
zac76156's Avatar
 
Join Date: Mar 2005
Location: NE Oklahoma
Posts: 211
Default RE: Measuring Groups

Get yourself a cheap 6" caliper and measure outside to outside of the widest part of the group
zac76156 is offline  
Old 09-21-2005, 08:24 PM
  #4  
Nontypical Buck
 
JoshKeller's Avatar
 
Join Date: Feb 2003
Location: Martinsburg, WV
Posts: 3,215
Default RE: Measuring Groups

Get some string, wrap it around all the arrows, and then measure the string length
JoshKeller is offline  
Old 09-21-2005, 09:08 PM
  #5  
 
Join Date: Feb 2003
Location: Blissfield MI USA
Posts: 5,293
Default RE: Measuring Groups

That would be the circumference and will be much larger than the diameter. Just measure the distance between the two farthest arrows. I just use a tape measure.

Paul
Paul L Mohr is offline  
Old 09-21-2005, 10:54 PM
  #6  
 
Join Date: Sep 2005
Location: center tx
Posts: 370
Default RE: Measuring Groups

the measure the distance from the center to center of the two arrows that are the farthest apart
gonzodemon is offline  
Old 09-22-2005, 06:50 AM
  #7  
Nontypical Buck
 
BGfisher's Avatar
 
Join Date: Feb 2003
Location: Middletown PA United States
Posts: 3,625
Default RE: Measuring Groups

What gonzo said. Center to center of the two widest shots.
BGfisher is offline  
Old 09-22-2005, 11:20 AM
  #8  
Nontypical Buck
 
Bulzeye's Avatar
 
Join Date: Feb 2003
Location: Too close to Chicago
Posts: 3,337
Default RE: Measuring Groups

I always measure center to center too.
That way the value you end up with is not affected by the arrow diameter itself. It only mesures the difference in the points where the arrows impacted.

If 2 shooters can put their arrows's centers inside a 1 inch group, the one with the smaller diameter shafts will have the smalllest group if you measure the outside, even though both produced the same level of precision.

It's like shooting guns. A guy with a 22 could shoot poor groups, and stillhave smaller groups thana guy with a 45 that shoots better if you measure the outside. On the other hand, the 45 is more likely to score higher on a target and hit more tissue on an animal.

For actual group size, you want the center-to-center number.
The easiest way to measure it, assuming you want more than eyeball accuracy, is to combine what Zak and Paul said. Measure the outside of the group with a caliper, and then subtract one bullet diameter to calculate the center-to-center.
Bulzeye is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Hammer49
Black Powder
5
11-16-2008 06:24 AM
Pioneer2
Reloading
7
10-02-2008 11:58 AM
mauser06
Guns
9
07-01-2007 07:51 PM
WinchesterX150
Black Powder
21
04-14-2007 12:36 PM
Duffy
Guns
7
09-29-2004 07:44 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Quick Reply: Measuring Groups


Contact Us - Manage Preferences - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.