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Yup. You have to fix those first. Until those are out of the way, what I posted doesn't work. And it's not always easy to fix them!

Most of my rifles with the exception of the ones for target and varmints are issue factory. They don't shoot as well the more shots I fire. This is a general statement and thats true of all shooting. I am quite satisfied with a three shot group with the point of impact of the first shot being of primary interest and not the groups.

On your side a guru of modern statistical quality control, Dr. Deming, was ignored by the USA automakers and Japan welcomed him. The rest is modern manufacturing history. More recognition is due to you and other cutting edge engineers and QC profesionals.



"The W. Edwards Deming Institute® is a nonprofit organization that was founded in 1993 by noted consultant Dr. W. Edwards Deming.

The aim of the Institute is to foster understanding of The Deming System of Profound Knowledgeâ„¢ to advance commerce, prosperity and peace.

Participation in The W. Edwards Deming Institute® means that we share Dr. Deming's vision of a better world. We participate because we strive, with joy, to carry on the work that he began. We seek to conduct ourselves in a manner consistent with his high moral and ethical standards, professional and personal integrity, and commitment to lifelong learning. We do this solely from our dedication to the philosophy and values of Dr. Deming and our belief that together, with humility, we can and will make a difference in the quality of life for everyone."

For rifles, I myself use 5 shot groups to validate the grouping for any particular rifle/round combination. Of course, I let the barrel cool down in between shots.

However, when you are talking true "averages," anything less than 30 samples (i.e. 30 shots) are considered a small sample size in the statistics world and special rules therefore apply. I always find it funny for someone to claim that a rifle has been verified to shoot "0.5 moa out of the box" because a target with 3 holes on it was included in the box. I think a lawyer could easily take some industry engineers (who should have all taken statistics classes in school) to task in a civil court forum. I hope such a day never comes though. Nevertheless, that is statistics for you.

There was a gun writer recently who suggested that rifle shooters should be shooting at least 30 rounds to validate grouping. Rather than shooting 30 shots all at once though, and then measuring the holes, he suggested that usually its better to shot either 6 5-shot groups or 10 3-shot groups, and then average the sizes of each group. This is a bit much for me, and probably won’t make much of a difference, IMHO.

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anything less than 30 samples (i.e. 30 shots) are considered a small sample size in the statistics world and special rules therefore apply

Absolutely.

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he suggested that usually its better to shot either 6 5-shot groups or 10 3-shot groups

Those two approaches will give you very different results! As a couple of posters have said, groups never tighten up as you add more shots.

I seem to recall reading a artical in which the author stated, as do some here, a single 3 or 5 rd group was a poor repesentation of a rifles true hunting accuracy. The thought was most game was taken with the first shot or two from a cold barrel and any more shots in a single group were not in line with shots fired at game under normal conditions. The author recommended firing the first one or two rounds from a cold barrel at a target and returning repetedly over a few months under different conditions and firing another round or two from a cold clean barrel on the same target. The idea was the group gathered over the firing of these couple dozen rounds was the best way to verify the true accuracy of ones rifle under hunting conditions.
He was likely on to something as the groups and POI will change under the different lighting, wind, temps, fatigue and other factors affecting our shots.
I personally work up my loads with three rds of each loading and fire four, five rd groups - 20 rds, one box - for accuracy when I feel I`ve reached the best one.
I trust this to show me the average accuracy I can expect of the load and trust if I made a +/-.25 MOA mistake in evaluating it the error will be moot in the field. Then I don`t shoot at ranges over 250-300 yds...........

I may get ran out of town for this but I think that generally the best accuracy is going to be found just below maximum velocity, so my load development thesedays consists of chronographing single loads up to that level with different bullets/powders and then testing the loads with three shot groups. If I feel that I got a flyer, I will add extra shots but generally I feel that three shots give me a good idea of a given loads potential.

Naturally, the closer I get to "the" load the more I will shoot.

I use five round groups on standard rifles, and three round groups for Magnum rifles. I cronograph 99% of all shots, mark the targets and staple the cronograph tape to the targets. My hunting loads will get one shot cold barrel tests at all temperature levels on single targets then they are superimposed over each other to determine the cold barrel group at whatever the conditions may be. Good shooting.

Gentlemen,

These posts express quite a few excellent views on effective methods to test rifle accuracy and/or verify zeros. I do not disagree w/ any of them, but I do disagree w/ suggestions that one method is superior to all others in all situations. Such a method does not, has not and will never exist.

We can continually dice and cut this topic to pieces. To start w/ most (not all) shooters I've encountered do not know how to measure their groups regardless of how many rounds were fired. There are numerous methods w/ reasoning to measure your group. We could argue for several pages on what method is superior. Most do not have a clue that they'll have a different zero shooting from different field positions vs. a bench. I've known Olympic shooters that shoot no less than 20-30 shot groups and believed that anything less has little value.

For new shooters out there, If your end game is hunting, I feel it is more important to use a bullet at a velocity that works for your intended game. Have a reasonable expectation of accuracy, example: one would do well w/ a 2MOA rifle for deer w/in normal shooting distances. I'd suggest shooting groups in the 3-5shot range at a reasonable zero distance. I would further suggest starting your string w/ the barrel in the condition you'd hunt with. I've in hunted conditions that if I left my barrel fouled from previous shooting, it would rust overnight. Also, I think it is reasonable and realistic to shoot your string straight away as this is realistic to firing repeated shots in a hunting situation.

Outside of that, get off and away from a bench. Spend more trigger time shooting from realistic hunting positions. Eventually you may find a method that best suits you. It's all good!!

This is just my opinion based on my training and life experiences.

Gary

I can take a poor load and shoot a tighter group than a person who is a poor shot who uses a good/proven load--so what does that prove?
One shot or 100 it doesn't matter! If you are having fun then enjoy the moment.
Personally, if I were happy with a 1"--1 1/2" group then I would leave my rifle at home and use my "SHOTGUN".

To test for definitive accuracy at the range I'll shoot 5 shot groups. To simply check a load to see if it's still accurate I'll go to 3 shot groups, but only for confirmation purposes. When my ship comes in, and I'm no longer in the same financial boat with mere earthlings I'll probably switch to 10 shot groups. Regardless of the number of shots in your group, take your time and don't shoot while that barrel is hot. It's just a waste of time and money. Best wishes.

Cal - Montreal

Longbob,
If you had to shoot a buffalo 9 times, it was either your caliber and load or your shooting.

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Personally if I were happy with a 1 to 1 1/2" group then I would leave my rifle at home and use my "SHOTGUN".

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Very well said

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Originally posted by Jarrod:
Longbob,
If you had to shoot a buffalo 9 times, it was either your caliber and load or your shooting.

It was neither. It was the buffalo. Some buffalo just don't want to die and this was one of them. Unless you are able to hit their CNS on a buffalo like this one, they will not be anchored. We didn't want him getting to the thick stuff, so we took the necessary measures we could to stop him. When you have the experience of hunting buffalo, then you will understand this a little better.

The number of shots I use depends on where I am with load development, which rifle I am working with, and whether its a new to me caliber, and what information I am trying to achieve.

Assuning a new rifle and a new caliber, and further assuming I have spotty or unreliable data. In this case I usually start with 1 or 2 rounds each, each round loaded with a tenth of a grain more powder. I normally have a spread of at least 2 granins of powder. If I am realy in the dark I might have this spread across as many as 4-5 grains, and the increments will get spread to 1/4-1/2 gr. The purpose of this exercise is to get a feel for pressure signs and my choice of powder and bullet type. Yes I occasionally end up pulling bullets on rounds, and yes this would be easier if I have a portable relaoding setup to take to the range (I am working on that). The whole drill is about pressure indications when I am loading if I have three rounds loaded I will print groups, but at this point I am fishing. Another point is I might be running side by side tests of different powder types.

Next I usually will refiine a varaint of the above, less spread, for sure 3 rounds loaded per and only 4-5 different powder charges with usaully 1/10 gr difference between them.

After all the above is done, I have completed the experimenting, and one or two loads are downselected, I start loading 5 rounds each, I may or may not do identical loads with different primers, depending a a judgment call on my part based on what I am seeing at the range.

From that point forward I shoot 5 round groups, but again this depends on the rifle. For long range rifles I shoot the box, 20 rounds on four targets: upper left shoot, five clicks of the scope right, shoot: 5 clicks down shoot, 5 clicks left shoot, 5 clicks up shoot. Repeat until you have shot 4 ea 5 round groups. The number of clicks varies depends on your targets and depends on the MOA adjustments on your scope, on one of my rifles its a 1/4 MOA adjustments, and my target are 8 MOA apart, so this is 32 clicks on that rifle.

The above really tests your hardware, load, rifle, snd scope. On most of my light sporters I set these up for the classic 4" tube, 2" high at 100 yards, and figure where my bullet has fallen to 2" down, at whatever range call it "X". Once done I leave them alone. I don't bother with the 20 round group, the rifles I do take to this level I am looking for .5 MOA average on the four targets, and no most rifles don't cut it, I have two rifles in my whole collection that will do it consistently, it is the utlimate test of rifle, load, and scope. Again in a sprter grade rifle I seldom bother, it has to be an exceptional rifle and load combo, before I even bother with this test. I have been both pleasently suprised, and shocked on testing sporters on this. A really good sporter can get into the slightly over 3/4 MOA category though, and I have tested some that while shooting great groups on a single target, fall flat on there face as soon as you touch the scope.

Let also state that the above is the worst case scenario, on rifles I know, on cartridges I know, I cut through a lot of the above testing, its a lot simpler to work with a rifle I know shoots, and I am trying out a new bullet type, a box of 20 rounds with various powder charges might be all I need to test in that case.

In short I use 3, 5 and 20 round groups depending on my application. And yes on certain rifles it takes several trips to the range and fair amount of time to make me happy. This is one reason I am so hesitant to add additional calibers to my reloading efforts, I load for just about all the standard calibers, many of the magnums, and several wildcats. Anything new at this point runs the is it redundant to something else I am already loading for, and do I really need it or want it test. I am not saying I don't add chamberings to my reloading portfolio, but brand new are usually very time consuming, and that is a commodity unfortunatly that is short supply. I just don't have the time to spend hours on my bench llike I used to.

PS:

The only time I shoot 10 round groups is when I am testing two 5 round groups of different loads on top of each other, and thats to see what point of imapct change I have between the two loads.

My .02 worth.

Testing loads, I shoot 5 sot groups.

When I think I have found that "magic" load, then I'll shoot 3 shot groups.

I working on trying to "dope" the wind but watching the conditions before I pull the trigger. It's kinda fun at 200 yards.

I think "doing" is more fun that theorizing about it.

3 shot or 5 shot groups?

You also need to ask how many of each type group is shot to have an idea how well you know the accuracy of the rifle.

I trust Denton's calculations and he says (10) 3-shot groups provides different statistical results than (6) 5-shot groups. I would have guessed you would have similar results if the total number of shots were the same.

I use 3-shot groups when dealing with light, hunting rifles. I have considered (5) 3-shot groups to be a decent indicator of the rifles accuracy (no math to back this up, just observation). I chose 3-shot groups to eliminate barrel heat influence as much as possible. The lighter the barrel, the quicker it heats (same thermal load with less mass to distribute the heat equals higher temp).

Denton, at what point does barrel heat become a "special cause" where the data is no longer normally distributed? Not an easy question to answer and I'm sure it varies from rifle to rifle. Rightly or wrongly, I've used multiple 3-shot groups in an attempt to avoid barrel heat as a special cause.

Sure would be interesting to know the statistical difference between (5) 3-shot groups and (3) 5-shot groups.

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Originally posted by GaryVA:
Light sporting contour hunting rifles, I'll generally use 3-shot groups for load development and sight adjustments. Example is my Remington UL light contour 270.

I'll use 3-5 shot groups on medium to heavier sporting contour hunting rifles. Example is my Winchester medium weight M70 30/06.

On varmint, target, and professional(Military/LE) rifles, I'll use 10-shot groups. Example is my Chandler M40 308.

Gary

Gary,

I use 2 shot groups when working up reloads. I'll usually work up a load in five or six steps so i get 5 to 6 2 shot groups. It gives me a idea of the precision of the powder. Also gives me an idea of the vertical stringing of the load as powder is increased.

Once I've worked up a load, I use 3 shot groups to check precision of rifles with light contour barrels. If you'll do this for 3 or 4 different ranges you'll also get a good picture of the trajectory of the load/rifle combination.

Use 5 shot groups for rifles with heavier contour barrels. Use same 3 to 4 groups at different ranges to check trajectory. Also spend more time on these to get the click numbers for my scope at longer ranges. Keep these scope click setting in a small notebook in the rifle case. Here's a target I shot "dialing" in my 270. The arrow from below off the picture was from the group 20" lower.