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Simple Minded improved group size recording - LR1955 - 12-15-2020
Lemonaid Wrote:Kicking around a better method of evaluating loads for accuracy. An easy way to account for 5th shot syndrome (4 nice shots in .250 and the 5th opens it up to 1.3 inches). A quick net search got me this link. https://bisonballistics.com/articles/optimal-group-size-for-rifles. The Radial Standard Deviation method would be great, those that use it please comment on how you like it and how you record the data to compare your loads.
My Simple Minded method is to use a clear template with circles lines like a target, say .5 inch center and .5 between circles and scored like a target, 10 points for each shot inside the center circle, 9, 8, 7, etc for shots that land in the corresponding outer circles.
Place the template on a five round group for max score, record the total for easy comparison.
Suggestions? Helpful criticisms? Better ideas? All welcome!
Back to the original message here. Lemonaid, I think this device is really good. Good because it is easy to use and is quantifiable. Yes, you can use it to find mean radius which is a more technical description of group size than minutes of angle. I used to measure groups in terms of mean radius but it was time consuming to find the center of the group. This template will do so pretty easily.
What I like about it is that it gives you two ways of describing your group. First is mean radius and second is score. By recording a score, you are giving yourself something akin to a probability figure as well as a mathematical record of how small your group was even with one shot that may be an outlier. Or a more open group because although the score was OK, the mean radius was bigger than other groups you recorded.
What to do with outliers? Depends on what you want out of the data.
If you want a total view of the load in terms of the probability that you will shoot a certain score at distance, then you need to include shots you blew because human error needs to be part of assessing probability when it comes to marksmanship.
If you want to make a assessment on the purely technical performance of your ammo and rifle combo without you involved, you can throw out shots you called out and went to your call. This assumes you can call your shots extremely well because if you call a shot wide at 3 and it goes wide at 8, it didn't go to your call and you need to record that shot.
Another thing you can do is shoot five groups of five and throw out the best and worse. Then average the remaining three. Personally, I think this is probably a better way of total assessment.
Like most here though, I shoot for groups at 100 yards only to see if a load has potential. If it has potential, I move my testing to 300 yards to compare two or maybe three loads that were good at 100. I do not think that shooting groups at 100 is a measure of performance. I view 300 as a much better distance to measure performance. I do not waste any more time an ammo on seeing how good groups are. When I find a load I think is good, I use it.
LR55
Simple Minded improved group size recording - Enrico Togni - 02-16-2021
Lemonaid Wrote:Kicking around a better method of evaluating loads for accuracy. An easy way to account for 5th shot syndrome (4 nice shots in .250 and the 5th opens it up to 1.3 inches). A quick net search got me this link. https://bisonballistics.com/articles/optimal-group-size-for-rifles. The Radial Standard Deviation method would be great, those that use it please comment on how you like it and how you record the data to compare your loads.
My Simple Minded method is to use a clear template with circles lines like a target, say .5 inch center and .5 between circles and scored like a target, 10 points for each shot inside the center circle, 9, 8, 7, etc for shots that land in the corresponding outer circles.
Place the template on a five round group for max score, record the total for easy comparison.
Suggestions? Helpful criticisms? Better ideas? All welcome!
Hi Lemonaid, hope you are ok. I read the very interesting article as per your link and I thank you for sharing it. It appears that 7 shots group is a good compromise when seeking for the best ammo/reloading/rifle matching. What I am not able to understand is how many groups ,for a any ammo/reloading sample, one should fire in order to get a meaningfull result?
Simple Minded improved group size recording - Sinclair - 02-16-2021
Enrico Togni Wrote:Hi Lemonaid, hope you are ok. I read the very interesting article as per your link and I thank you for sharing it. It appears that 7 shots group is a good compromise when seeking for the best ammo/reloading/rifle matching. What I am not able to understand is how many groups ,for a any ammo/reloading sample, one should fire in order to get a meaningfull result?
Years ago, in a Sierra reloading manual discussion on group size and accuracy, Sierra technicians suggested shooting groups of 7 or 8 rounds. They found that this practice gave statistical results equivalent to shooting 100 rnd groups. As far as how many groups, I do not remember, but IIRC they only shot one group per test. The more shots fired, the more extraneous factors become significant statistically. As we are all aware, it is very difficult to duplicate the exact conditions, whether environmental, physical, or mental over a long string of shots.
Simple Minded improved group size recording - Enrico Togni - 02-16-2021
Sinclair Wrote:Years ago, in a Sierra reloading manual discussion on group size and accuracy, Sierra technicians suggested shooting groups of 7 or 8 rounds. They found that this practice gave statistical results equivalent to shooting 100 rnd groups. As far as how many groups, I do not remember, but IIRC they only shot one group per test. The more shots fired, the more extraneous factors become significant statistically. As we are all aware, it is very difficult to duplicate the exact conditions, whether environmental, physical, or mental over a long string of shots.
In fact shooting two or more groups of same loads, beeing all equal ,even a few minutes apart, always gives me pretty different results. I don't know other shhoters but for me is so, whaterver I pay attention to shoot at my best.
Simple Minded improved group size recording - Oryx - 02-17-2021
Its also helps when shooting for groups to use a separate POA and POI. Adjust your sights to impact away from aiming point so that you an concentrate on an unaltered POA and not chase last rounds ... keep the focus on the alignment and execution.
Simple Minded improved group size recording - Enrico Togni - 02-17-2021
Oryx, do you perhaps mean shooting , say for a typical 5 shots group, 1 shot each per 5 different targets and then making a stack of those and calculating the dimension of the obtained group as a aggregate?
Simple Minded improved group size recording - Lemonaid - 02-17-2021
Enrico Togni Wrote:Oryx, do you perhaps mean shooting , say for a typical 5 shots group, 1 shot each per 5 different targets and then making a stack of those and calculating the dimension of the obtained group as a aggregate?
I believe he means moving the cross hairs in your scope say 8 clicks up or 8 clicks left so that your point of aim can remain undamaged from bullet impacts and also your focus won't be on the group, but on the unchanged target. If I am wrong or giving a incomplete explanation, Oryx please correct.
Simple Minded improved group size recording - Lemonaid - 02-17-2021
Enrico Togni Wrote:Hi Lemonaid, hope you are ok. I read the very interesting article as per your link and I thank you for sharing it. It appears that 7 shots group is a good compromise when seeking for the best ammo/reloading/rifle matching. What I am not able to understand is how many groups ,for a any ammo/reloading sample, one should fire in order to get a meaningfull result?
A deep dive into this subject was explained by Precision Rifle Blog (see Summary).https://precisionrifleblog.com/2020/12/12/measuring-group-size-statistics-for-shooters/ It answered many of my questions and concerns. What I am doing now it 3 shot groups to find best bullet seating depth, then a 10 round group of the best for score/record.
Simple Minded improved group size recording - Oryx - 03-20-2021
Lemonaid Wrote:I believe he means moving the cross hairs in your scope say 8 clicks up or 8 clicks left so that your point of aim can remain undamaged from bullet impacts and also your focus won't be on the group, but on the unchanged target. If I am wrong or giving a incomplete explanation, Oryx please correct.
This exactly. ^^
Both points help out tremendously in my experience.