March
S M T W T F S
1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31
Who's Online Now
0 members (), 1,244 guests, and 3 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums10
Topics38,374
Posts544,014
Members14,391
Most Online1,131
Jan 21st, 2024
Previous Thread
Next Thread
Print Thread
Page 2 of 2 1 2
Joined: Jan 2002
Posts: 5,954
Likes: 12
Sidelock
***
Offline
Sidelock
***

Joined: Jan 2002
Posts: 5,954
Likes: 12
If you are deeply interested in patterns, read Dr. Andrew C. Jones's book, "Sporting Shotgun Performance - Measurement, Analysis, Optimisation." Dr. Jones deals with statistically viable data. Data is obtained by feeding a computer program digital photos of patterns. One of the most enlightening findings is that patterns have so much variability that one must have ten (10) patterns with the same factors to get reliable data. This sort of data is capable of predicting "X" hits on a target at given range. Now that is a true prediction of performance.

Rifle fire uses the same type of statistics. Should you shoot 3 shot groups? 5? 10? How about 600! (sounds suspiciously like a shotgun pattern, no?)

I have no idea why O & T did all that work and then fell flat with their analysis.

DDA

Joined: Jan 2002
Posts: 13,127
Likes: 1129
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2002
Posts: 13,127
Likes: 1129
Don, to play the devil's advocate, do you have any idea why Jones fell upon the number 10?


May God bless America and those who defend her.
Joined: Jan 2002
Posts: 5,954
Likes: 12
Sidelock
***
Offline
Sidelock
***

Joined: Jan 2002
Posts: 5,954
Likes: 12
Yes, Stan. In statistics there are equations that predict how confident you may be in conclusions based on the variability of data and how much data you can gather. One such equation is "R-squared." It is a good predictor of how much data you need. For example, my little MOI machine has "R-squareds" of , usually, better than 99.9%. In said case, I would be safe with one data point. Note that the weight, balance, and MOI of any single gun does not vary. The only significant source of variability is bearing drag or weather vaneing in a strong air draft. With patterns there are many variables that may/may not be significant. I would take a SWAG that Jones used R-squared in his decision as to the number of data points required.

DDA

Joined: Jan 2002
Posts: 13,127
Likes: 1129
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2002
Posts: 13,127
Likes: 1129
That's about as good an answer as I can understand, Don. Thanks!


May God bless America and those who defend her.
Joined: Jan 2002
Posts: 5,954
Likes: 12
Sidelock
***
Offline
Sidelock
***

Joined: Jan 2002
Posts: 5,954
Likes: 12
IMO, a lot of misinformation has been passed to shooters over the years. O&T should have understood what was required for proper analysis. I guess they were unable/unwilling to invest the resources to do it manually, even with semi-slave student labor, like Jones and his trusty computer do it.

I'm aware of master barrel borers shooting patterns and "tinkering" with the choke until they got the pattern they/the customer desired. Never heard of anyone firing nine more patterns for verification.

Joined: Jan 2002
Posts: 13,127
Likes: 1129
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2002
Posts: 13,127
Likes: 1129
I have fired scores of patterns (not thousands) at paper and my grease plate over the last 40 years or so. I have never found the need for statistical analysis of shotgun patterns. Not saying there isn't a need, just that I have not had one. My main purposes for patterning a shotgun are:

1) to determine if a doublegun's patterns are regulated, and to determine to what extent they shoot to point of aim
2) to determine what load they are regulated for
3) to determine the approximate percentage of the pattern of a certain load

Beyond that it is is "too much sugar for a dime", for me. Once regulation is determined, and the best load for the gun and purpose, I just need to shoot it, because at that point I have confidence in the gun and load. And, it's hard to overstate the importance of that, IMO.


May God bless America and those who defend her.
Joined: Jan 2002
Posts: 5,954
Likes: 12
Sidelock
***
Offline
Sidelock
***

Joined: Jan 2002
Posts: 5,954
Likes: 12
#1, absolutely. #2 & 3, not, IMO. You are drawing a conclusion about a choke/load/distance/target area based on much too limited data. The ten patterns to draw valid conclusions still applies, IMO. Conclusions based on statistical unreliable data are, well, unreliable. IMO.

DDA

Joined: Jan 2002
Posts: 13,127
Likes: 1129
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2002
Posts: 13,127
Likes: 1129
How can you disagree with #2 and #3 Don, when they make no hard statement about any general principle? They are two of MY purposes for patterning a shotgun. If you read closely you will see that neither make a broad, sweeping statement about patterning, in any way. They are MY purposes. You may not agree with my reasoning for having these purposes, but you can't reasonably disagree with my opinions for myself. You can state that my principles are at fault, but my decisions on the level of accuracy necessary for me are mine. I have killed a limit of doves without a miss, a limit of 6 ducks with 6 shells, and have shot two 100/100 on sporting clays courses. Do I have to do each 10 times to have a valid statistical reference about my loads in each circumstance? I guess the answer may be "yes", and that without 10 replications it means nothing.

I just cannot see how determining the APPROXIMATE percentage of a load requires 10 shots, over 5? Remember, I said approximate. (The expectations here are the key. Actually, the expectations are the real reason for choosing 10 over other lesser numbers, are they not?)


May God bless America and those who defend her.
Joined: Jan 2002
Posts: 11,372
Likes: 103
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2002
Posts: 11,372
Likes: 103
Re Dr. Jones, I recall that he came to some conclusions about skeet and single pellet breaks that, I think, pretty much surprised skeet shooters. Jones' analysis concludes that they're relatively common. Personally, that caused me to wonder whether maybe he needed to walk away from his computer, stroll around on a skeet field, and see how many unbroken targets he could find with holes in them. Plenty with one hole . . . some with even more than one. While his analysis might predict the likelihood of single pellet hits, can it predict the likelihood of single pellet breaks? The simple exercise of examining unbroken targets clearly shows that single pellet hits often fail to produce single pellet breaks.

Page 2 of 2 1 2

Link Copied to Clipboard

doublegunshop.com home | Welcome | Sponsors & Advertisers | DoubleGun Rack | Doublegun Book Rack

Order or request info | Other Useful Information

Updated every minute of everyday!


Copyright (c) 1993 - 2024 doublegunshop.com. All rights reserved. doublegunshop.com - Bloomfield, NY 14469. USA These materials are provided by doublegunshop.com as a service to its customers and may be used for informational purposes only. doublegunshop.com assumes no responsibility for errors or omissions in these materials. THESE MATERIALS ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANT-ABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. doublegunshop.com further does not warrant the accuracy or completeness of the information, text, graphics, links or other items contained within these materials. doublegunshop.com shall not be liable for any special, indirect, incidental, or consequential damages, including without limitation, lost revenues or lost profits, which may result from the use of these materials. doublegunshop.com may make changes to these materials, or to the products described therein, at any time without notice. doublegunshop.com makes no commitment to update the information contained herein. This is a public un-moderated forum participate at your own risk.

Note: The posting of Copyrighted material on this forum is prohibited without prior written consent of the Copyright holder. For specifics on Copyright Law and restrictions refer to: http://www.copyright.gov/laws/ - doublegunshop.com will not monitor nor will they be held liable for copyright violations presented on the BBS which is an open and un-moderated public forum.

Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.0.33-0+deb9u11+hw1 Page Time: 0.055s Queries: 33 (0.034s) Memory: 0.8348 MB (Peak: 1.8988 MB) Data Comp: Off Server Time: 2024-03-29 06:19:33 UTC
Valid HTML 5 and Valid CSS