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Post by wfa on Jun 27, 2015 10:58:54 GMT -8
When evaluating a new rifle/barrel my minimum number of rounds in a "group" is seven or more. IMO, for a "hunting rifle" the most important shot is the first shot, with a second and third shot being "interesting"; for a "target rifle", or when doing load development, the more shots the better (even in "ladder testing" more is better, but "more" does defeat the "cheap and easy" idea).
I used to own (notice USED) a Ruger #1 that was a "tack driver" for shots 2 through "n", but the first shot was a crap shoot (no pun intended) - it could go anywhere. I tried clean, dirty, dry, "wet", the first shot was clearly in the hands of God. As a hunting rifle it was useless to me, so it got traded away. If that rifle had placed the first shot at POA, with the rest going who knows where, I'd still own it. I still own a Garand chambered in "308" that will put the first clip (yes, it's a clip, not a magazine) into 1.25 MOA, then opens to 2 or more. I don't shoot it very much anymore, but I still own it because it's PREDICTABLE, and when the barrel cools, it's right back to where it started.
My preference for groups of seven shots or more is based on statistics and "set theory". I'm probably an "Army of one", but I'd like to know what you folks think.
Walt
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Post by bobatl on Jun 28, 2015 13:52:16 GMT -8
"set theory", is that a yoga thingy ?? 
straight answers: 3 for load workup looking at speed and pressure signs, 5 for accuracy at range, 10 for when 22 LR were cheap, plus I had more patience way back then. |
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Post by mosigdude on Jun 29, 2015 8:30:18 GMT -8
straight answers: 3 for load workup looking at speed and pressure signs, 5 for accuracy at range, 10 for when 22 LR were cheap, plus I had more patience way back then. + 1 3 for load development - looking for accuracy potential, very general speed and pressure 5 for fine-tuning the better loads from above with slightly lower and slightly higher (assuming I was not already at max) powder charges and sometimes tweaks in seating depth |
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Post by wfa on Jun 29, 2015 15:09:22 GMT -8
I suppose I should cite a reference for my opinion. geoffrey-kolbe.com/articles/rimfire_accuracy/group_statistics.htm is a source. For those not wishing to wade through this whole paper, I'll "cut to the chase". "The other point of interest is that the most efficient number of shots to shoot in a group is seven. The number of shots tabulated in Table 3 is rounded up or down so the numbers correspond to complete groups, which means the results are a little lumpy. But as the tolerated error decreases and the number of shots grows, the quantization of the group number has less effect and the seven shot group starts to stand out as the most efficient. Seven shots in a group is the best balance between knowing where the centre of the group is and the average contribution of each shot to the measured size of the group. It is common to shoot five shot groups and it can seen that shooting five shot groups is almost as efficient as seven shot groups. Ten shot groups is a little worse than five shot groups and 3 shot groups is worse yet. As for 20 shot or more groups - a waste of good ammo. Given that rimfire ammo comes in boxes of 50, which is neatly laid out in rows of 5, shooting five shots groups would appear to be the best balance of practicality and efficiency. It should be noted here that the first mention (to my knowledge) that the most efficient number of shots in a group for the Extreme Spread method is seven, was by G.Sitton in the "Handloader" magazine, (September-October 1990, starting page 42) who communicated a statistical analysis by Ken Kees and Dr. Banister of Speer Bullets." At one time I had a copy of the "Handloader" article, but it, too, was lost in my house fire. ballistipedia.com/index.php?title=Range_Statistics is a bit easier to read (I just found this site). Walt |
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Post by GLSHOOTER on Jun 29, 2015 15:58:55 GMT -8
Proving the load once you think you have it seems to be five five shot groups. It will show, for me, just exactly what I can expect day in day out on the + or - side. Of course the outstanding thing about the whole exercise is that the "best" today has little relationship to the "best" in five hundred rounds. Chasing the lands thanks to throat erosion is all you can do and may be as productive as taking a fistful of $5.00 bills into a strip joint. Hope all you want but at the end of the day you take what you can get.
Greg
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Post by Deleted on Jun 29, 2015 16:26:21 GMT -8
I wonder if we should alert the NBRSA and let them know, "We have been doing this all wrong for all these years". I'm not sure you would even get your call returned. 5 shot groups have been the norm for as far back as I can remember. By the way loading blocks used in a bench rest match are made in banks of 5.
If you want to see what a rifle can do, shoot a 5 shot, 5 target aggregate. It will show way more than what the barrel is capable of. In most cases the barrel will make far fewer mistakes than the shooter. 7 shots is a waste of ammunition. It will prove nothing except you pulled the trigger 2 additional times.
I guess if you feel real froggy, try a 10 shot group. If you can keep them under a .100 you can compete with the unlimited boys and their rail guns. Which is the only place more than 5 shots are a reasonable scenario.
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Post by wfa on Jun 30, 2015 6:38:36 GMT -8
Sir, I agree with what you are saying, but it appears I haven't made myself clear. My point was/is that when developing a new load for a rifle seven shots should be considered. If you are shooting many 5 shot groups, or you have previously established a certain load is "the best" (as in the case of competition where you are demonstrating both your skill and the rifle's precision), then two extra shots are a "waste" or "illegal". However, when evaluating a load which "shows promise" (as in a ladder test), or trying to pick "the best" from two different promising loads, seven is better than five. I'm not about to load seven rounds to confirm that a four inch, three shot group is "bad", but if I have two loads which both shot "bug holes" for three shots, the next step would be seven of each. The smaller of those two seven shot groups has a higher probability of being the better group than had I shot five shot groups.
As I wrote from the "git go", this is an opinion (with justification by some wiser than I).
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Post by GLSHOOTER on Jun 30, 2015 8:55:37 GMT -8
If five looks good, and I routinely shoot two five shot groups, I'll come back the next time and shoot a couple more. If it is so outstanding I can't believe it then the five shot five group protocol group comes into play.
Three shots tell me PDQ if I have a poor choice on my hands. A 3" three shot group in most of my guns means that my cartridge eraser will get a work out later the next day.
The heat here is a major factor in development of loads. Powders are weird, mirage is terrible and the sweat in my eyes burns something terrible. I chase the accuracy dragon to an established point in my mind. I save the final scalpel work for the next trip.
Greg
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Post by wfa on Jun 30, 2015 9:13:14 GMT -8
Alabama has just ended a 22 day string of 90F+/45%+ days, most 95F+. "I feel your pain!"  |
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Post by GLSHOOTER on Jun 30, 2015 14:08:00 GMT -8
Alabama has just ended a 22 day string of 90F+/45%+ days, most 95F+. "I feel your pain!" Yeah, throw 15-20 degrees on that and join me in my little bit of Hades...  Greg PS: Dry heat my hiney!!! |
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