I'm curious as to what shooters prefer when trying to develop a load? I normally shoot 5 shot groups for everything but was wondering if a 3 shot group is just as good. Does a 5 shot group tell you more about the load than a 3 shot group? Reading some of my old shooting books by Keith, Whelen, O'Connor, etc. seemed like the standard in those days were single 10 shot groups. Have we lost something in all of our technological progress??

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

3 shots is the test of the rifle,..5 shots is the test of the shooter. If she won't group 3,.she ain't gonna group 5. I shoot my load ladders round robin style to eliminate shooter error as much as possible. 5 shots are my load ladder number,..but after you get a good load,..3 is all you need to check zero. If she cuts 1 hole with 3 and number 4 jumps out,..that's the shooter, not the rifle.

I do 5 shot groups because that is how many rounds there are vertically in an MTM box.

-Spencer

Can you explain more about your load ladders round robin style?

I like athree shot group myself..........I can keep it together better for a 3 shot group I feel a lot less pressure.

quote:

Originally posted by Prewar70:
I'm curious as to what shooters prefer when trying to develop a load? I normally shoot 5 shot groups for everything but was wondering if a 3 shot group is just as good. Does a 5 shot group tell you more about the load than a 3 shot group? Reading some of my old shooting books by Keith, Whelen, O'Connor, etc. seemed like the standard in those days were single 10 shot groups. Have we lost something in all of our technological progress??

For a hunting rifle, a 3-shot group is sufficient, but it should be repeatable tomorrow or next year, if you are to have confidence in that particular load.

As a lightweight barrel heats up, one can almost expect the group to open also, so if you want to use 5 or 10-shot groups when testing hunting ammo, always let the barrel get cold between shots.

Sort of on the same subject...When you are firing test shot groups, how many shots do you take before letting the barrel cool down and how long will you wait to let it cool before you'll have another go? I ask because I've just started reloading and because it takes me an hour to get to the range I intend to take 4 or 5 different loads for testing.

I do 5...

I shoot 3 shots. If the load looks promising, I'll shoot 5 shots. Depending on the temp. I let the bbl. cool 1 minute between shots. I also take at least 2 rifles so I can switch back & forth between groups, let one cool, shoot the other.

Ditto to JustC.

3 is plenty, 5 is a waste. This only applies if you have good rest and are confident in your shooting ability. If you are confident on three rounds you will be able to tell if a particular load is worthy of another look.

Reloader

3 shots working up a group. When I get a promising load, I proof it with 10 rounds of very slow fire. I throw out the flinches (never can get 10 off without at least 1 little twitch), then call it a good test.

Once I have sighted in I shoot 2, yes dear friends, 2 shots per group. I have never needed more that two shots on any game animal unless it down but not dead yet. I shoot 2 out of a cold barrel, but I do it often. It takes more time but to me its a more true indicator of how things will be in the field.

I see great value in 5 to 10 shot groups. They test the rifle and shooter a great deal. But if hunting is on the menu its 2 shots for me. I try to do that at least 4 times a day in prep for a hunt. Thats 2 shots as fast as I can cycle the bolt and get back on target. Now having said that I do shoot 5 shot groups in load development just to insure against bedding problems or somthing else wrong with the rifle.

I see no use in shooting a five shot group and throwing out the first shot as a fouling shot and the widest shot as a flinch, that puts you back to a 3 shot group...................JJ

I've read that 7 shot groups give the best statistcal average of a gun/load combo.

a wide 3 shot group ain't gonna shrink if you fire more shots. However a small 3 shot group can easily be a fluke, and shots 4 and 5 can reveal that. By that I mean, a single 3 shot group can easily reveal an unacceptable load combo, but does not prove an acceptable one.

I shoot 5 shot groups during load development, and at the end stage will shoot 4-5 groups to get an average.

Only once have I had a small 5 shot group fool me into thinking it was THE load, subsequent groups were suprisingly poor , but many times 3 shots have looked promising only to have further tests prove different.

If you only shoot one 3 shot group, you really don't know exactly what you have.

5 shot groups should scare no-one off, honestly, If a gust of wind came up or you know before you looked that you didn't get off a clean shot, simply dismiss that shot, shoot one more and focus on the ones you know you did your part on.

For myself I see no point in going to the trouble and expense of loading up several hundred, or even thousand, rounds of ammo on an unproven load.

No load is proven till it can give you the results you desire repeatedly, not just once, with 3 shots..

My 2 cents

Ricky

Prewar70: I use 5 shot groups for my Rifle load development testing.
And for the last many years now I refuse to do ANY load testing when the air is moving!
This practice has made my load development so much easier (quicker) since I started doing it - that I highly recommend that you also wait out the wind and only fire your load development rounds when conditions are near perfect!
Hold into the wind
VarmintGuy

Oh, another reason why I do 5 shots is because 50 is not divisible by 3, but then again 60 is, so does this mean I need to buy more MTM R-60 boxes and do 3 shot groups? But then how would I keep track of them all at the range?

-Spencer

prewar70,..I began this method not quite a year ago after reading an article on Dan Newberry's OCW formula. The theory is that by firing one round of each charge at seperate targets, and running the ladder up 1 round at a time,..you more evenly disperse the human error across your data set. When I used to shoot them in charge range groups,..the human error could often make a good recipe look only so-so. BUT, once I started using the round robin style of shooting, the human error seemed to be much less evident, and the charge ranges where the rifle wants to be are VERY evident on the targets.

here is how it works when I do it. If I have say 8 charges ready to test, I put the smallest orange dot on the bottom of the target paper (2 per paper). I then set the target at 200yds to help with the match bullets and their stabilization. Now,..instead of shooting the charges in the columns of like charges (5 of each) I shoot the rows instead. So I aim the first charge at the first target, the second charge at the second target, the third charge at the third target, etc. Then let the barrel cool after each ladder is run. You now have one bullet hole for each orange dot. Once the barrel is cool, repeat the process each time until there are 5 holes for each target. I find the results to be amazingly similar between any multitude of calibers and bullets. There will be say 3 charges in a row that shoot very small groups, then 3-5 charges that resemble a heartbeat on a monitor (not good groups at all) I find that this takes a lot of that mental factor out when you are staring at a great group, but now put a lot of pressure on yourself to get the last 1-2rnds into that same hole. I really beleive this method is what works best for ME,..so give it a try and see what you get with it.

watch the progerssion on this ladder













You can clealry see what charge ranges it likes and those it does not like. My results were never that concise before I went to round robin style ladder work-ups rather than shooting 5 of a single charge in a row. I firmly beleive the error I introduced was the weak link, and this way seems to better disperse that. HTH

JustC,

Very interesting, I have never heard of that but am definitely going to give it a try next time. I appreciate you taking the time to put that together. I have always shot 5-shot groups but started to think I might save some time during load development if I switched to 3-shot groups. It would also give me the ability to try more loads. Then I could narrow it down to maybe 2 or 3, and then go for 5 or 10 shot groups. Or two 5-shot groups of each load and see what I come up with. Up till now, everything has been 5 shot groups.

Where the first bullet hits from a cold barrel is my primary interest. I record this and then fire one or two shots more for a group. Some hunt varmints and get multiple shots so for them a multi shot group would make sense.

For target shooting it could be a 120 shot match and at least a 10 shot group is what I would do.

How many shots you should shoot depends on how precise you need your answer to be. As you shoot more and more shots, you get a clearer and clearer picture of what the rifle will do, long-term.

The average size of three five-shot groups will tell you the long-term performance within plus or minus 25%. If three fivers average 1", then the rifle is between .75" and 1.25".

A single five-shot group will get you within minus 50 to plus 100%.

The math just doesn't support a three-shot group as being any kind of reliable indicator. The logic that you'd never shoot more than three times at an animal doesn't really apply in this case. The issue is how different from each other three-shot groups can be, just by random chance, and the answer is that they can be very different, with no change whatever in the gun, ammunition, or shooter.

denton,

My light contour LA rifle is a medium game hunting rifle only. From a clean, dry and cold bore w/in a temp range of approx. freezing to approx. 50deg, I can shoot from a solid rest three shots(smooth and deliberate, but back to back) at 200yards hitting a 2" circle. This rifle is approx. 12yrs old and I've used the same target since year one (one or two times a year)to confirm my 200yd zero. I've never shot out of this group w/ the first three shots. Beyond the third shot, the light contour barrel heats quickly and the additional shots begin to change POI. This method of 3-shot groups best suits me w/ this style of rifle.

My medium bore rifles do not suffer from the barrel heat and therefore I prefer 5-shot group/zero verifications.

My professional rifle (and to a lesser extent my varmint/competition rifles), I use up to 10-shot groups. I also use a round robin method to confirm my scope will track and come back to my base zero.

Savage,

In a precision rifle it is extremely important to keep track of your cold bore POI. One thing I've picked up over the years is, teflon and moly can really screw w/ you on the first round down range. W/ proper barrel maintenance, you can reduce that difference significantly provided you and your weapon are capable.

Gary

quote:

Originally posted by denton:
How many shots you should shoot depends on how precise you need your answer to be. As you shoot more and more shots, you get a clearer and clearer picture of what the rifle will do, long-term.

The average size of three five-shot groups will tell you the long-term performance within plus or minus 25%. If three fivers average 1", then the rifle is between .75" and 1.25".

A single five-shot group will get you within minus 50 to plus 100%.

The math just doesn't support a three-shot group as being any kind of reliable indicator. The logic that you'd never shoot more than three times at an animal doesn't really apply in this case. The issue is how different from each other three-shot groups can be, just by random chance, and the answer is that they can be very different, with no change whatever in the gun, ammunition, or shooter.

I don't agree with this at all in terms of a practical way to know that you can hit something from a clean cold barrel.

Just one fallacy of firing multiple shots is that the rifle heats up and it's no longer in the clean cold condition. Now if your testing your ammo, your aim or getting ready for a 200 shot match or ground squirrel event then fine but for big game hunting and even more the varmint hunting that many do a shot from a cold barrel settles the hunt right there.

I've never shot any game animal 5 times.

my barrel was CLEANED with Wipe-out and Kroil. My cold bore shots are much closer to the actual group when the bore is already fouled a bit, but once they are super clean,..they can often throw the first 6-10rnds high and right before settling in.

Once I settle on a load,..I'll check the cold bore for hunting accuracy, but rarely have to make more than 1-2clicks to dead zero from a cold bore. Now, keep in mind 90% of my ladders are run through select match grade barrels that have been stress releived which can and will change it's characteristics compared to a factory tube.

quote:

Originally posted by denton:
How many shots you should shoot depends on how precise you need your answer to be. As you shoot more and more shots, you get a clearer and clearer picture of what the rifle will do, long-term.

The average size of three five-shot groups will tell you the long-term performance within plus or minus 25%. If three fivers average 1", then the rifle is between .75" and 1.25".

A single five-shot group will get you within minus 50 to plus 100%.

The math just doesn't support a three-shot group as being any kind of reliable indicator. The logic that you'd never shoot more than three times at an animal doesn't really apply in this case. The issue is how different from each other three-shot groups can be, just by random chance, and the answer is that they can be very different, with no change whatever in the gun, ammunition, or shooter.

Those percentages are merely opinion, we can make a great statistical arguement on both 3 & 5 shot grouping methods but, the end results are solely dependant on each rifle tested.

I find much more merit in 3 shot groups over 5 shot groups w/ many rifles due to the fact that many rifles have flyers on the 4th & 5th shots vs the first 3. One fact for sure is if it doesn't shoot a good group on the first three it's not going to on the next two. A mere waste of ammo most times. There are too many varibles that cause fliers.

IMO, I would rather see a rifle shoot 5 consistent 3 shot groups from a cool clean barrel than 3 5 shot groups. It's all personal preference but no method is "Factually" better than any other.

Good Luck!

Reloader

quote:

Those percentages are merely opinion, we can make a great statistical arguement on both 3 & 5 shot grouping methods but, the end results are solely dependant on each rifle tested.

Not at all, sir.

Once you eliminate all "special cause", such as shooter flinch, and barrel rubs, then all that remains is normally distributed random error. The information I posted is based on the statistics of the resulting distribution of group sizes.

After doing all the work, I found that Audette had partially preceded me by a few decades, and that he published almost identical numbers for single five-shot groups. As far as I know, I'm the only one who has bothered to do the math on averages of three five-shot groups.

It's solid math. No opinion in it.

quote:

Originally posted by Jarrod:
I've never shot any game animal 5 times.

I shot at my Buffalo a total of 9 times. The first shot off shooting sticks, the second shot off my PH's shoulder as a rest. Number three through nine were sprint, shoot, sprint, shoot, etc.... I finally drowned him by weighing him down with so much lead.

The first shot was not from a cold barrel. It couldn't have been. We had been stalking this group all day in 110 degree heat.

denton,

You should know by now that you're wasting your time to educate people who will never be able to grasp the concept of of using statistics as a mathematical tool to analyze and interpret bullet holes in target paper.

This is what CCI recommends:

"A three-shot group may look great, but won't be representative of the entire ammo lot or your firearm. A statistical study conducted by our QA department showed that the fewest shots you can fire into one group and have a high level of statistical confidence for repeatability is seven. Your minimum shooting for each ammo type should be one 7-shot or two 5-shot groups. More is better."

When I work up loads, I shoot three-shot groups. If a rifle won't shoot three well, it isn't going to shoot five any better.

After that point, I shoot five-shot groups. You may not ever need five shots for any single shooting opportunity during a hunting trip, but I've been amazed at how often those two additional shots reveal glitches in the rifle or load that need to be sorted out.

I consider five-shot groups to be a fairer, more honest evaluation than three shot groups, but ten-shot groups are over the top.........

AD

quote:

denton,

You should know by now that you're wasting your time to educate people

There are some that get it, and that makes it worthwhile.

CCI's recommendation of two five-shot groups is still a little light statistically, but not bad. Three fives isn't that much stronger. Somewhere in the 2-4 five-shot groups is about the right tradeoff between precision and cost.

The full course free rifle match is 120 shots plus sighters so the rifle and ammunition must shoot a 130 shot group or more.

For the big game hunting and varmint hunting that I do the first shot impact and not some group from a cold barrel is by far the most important. Sometimes a second shot is necessary. Thats all the rifle and ammuntion has to do.

Those are my requirements. I am quite aware of statistics and the laws of probability and have a degree to back that up. But I have learned far more from common sense.

Thus I fire ten shot groups on target rifles and two or three shot groups with my sporting rifles because that's what they need to do at the range and in the field.

"If scientific reasoning were limited to the logical processes of arithmetic, we should not get very far in our understanding of the physical world. One might as well attempt to grasp the game of poker entirely by the use of the mathematics of probability."
Vannevar Bush
US electrical engineer (1890 - 1974)

I believe Denton is on the right track as far as getting significant information and drawing conclusions. Too, I initially will use three or five shot groups when developing a load, then "proof" the selected load with two ten shot groups. All development is done over chronograph and attention given to hi/low and SDs.

And added thought: because a rifle will group, say, MOA at 100yds does not mean that it will stay MOA at further distances. I have had rifles that will give the same group size at both 100 and 200yds and other rifles that will triple the group size from 100yds to 200yd under calm conditions. All my "proof" groups are fired at 200yds and I feel it is a far more reliable indicator of what I can expect in the field.

I'll be odd here.... I shoot 4 shots groups, and find tht usually I will have a 3 shot triangle, plus an odd shot, or "flyer". Forget the flyer, and judge the groups by the triangle.

quote:

quote:
denton,

You should know by now that you're wasting your time to educate people


There are some that get it, and that makes it worthwhile.

CCI's recommendation of two five-shot groups is still a little light statistically, but not bad. Three fives isn't that much stronger. Somewhere in the 2-4 five-shot groups is about the right tradeoff between precision and cost.

Denton,

I've had plenty of classes in Statistics, a subject I found much easier than any of the Lower Maths and Calculus classes I took while attending Engineering school. A good sound arguement can be said for each 3 shot groups and 5 shot groups BUT, there are no concrete solid variables in shooting. When you combine shooter error (the largest factor),SD of velocities, differences in bullet weight, variances in bullet shape (yes, even in the same lot/brand), primer charge variance, barrel fouling, wind, mirrage, etc, etc, etc, etc........., There are far TOO MANY variables to get solid mathmatical FACTs from the differences in 5 vs 3 shot groups. It is merely opinion and theory.

Denton, I'm not saying your math isn't right or your statistical analysis isn't correctly formulated but, if not in a vacuum under exact tollerances and mechanical means to eliminate the vast number of varibales in the equation, theres no solid facts that one is better than another. It's a matter of personal preference.

I personally feel confident enough to make better theories on the accuracy of certain rifles based on several three shot groups vs a few five shot groups. I actually find that to tell me more about the capabilities of that rifle. After all we are primarily talking hunting rifles any how.

Have you done any calculations on flyers? What about a series of groups that put three through the same jagged hole and throw two as much as 1.5" off?

I think we are basically after the same goals, a rifle that shoots consistently well. My main concerns are a load that consistently shoots well, I want my rifle to put the bullets in the same place whether I shoot it once a day or 25 times a day. Consistency is the key. I personally find it better to find this consistency from a string of 3 shot groups rather than 5 especially when weather is a concern(Again too many variables).

If a man thinks he has to shoot five shot or 25 shot groups find out the potential of his rifle, I have absolutely no problem w/ that at all, my hats off. He's still going to have loose variables in his effort heck, none of us are perfect by any means.

Have a great day!

Reloader

quote:

There are far TOO MANY variables to get solid mathmatical FACTs from the differences in 5 vs 3 shot groups. It is merely opinion and theory.

Then you missed the whole point of statistics.

When you have a few large variables, such as barrel rub, and shooter flinch, you treat them individually.

When you have many small variables, too many to deal with individually, you lump them together and treat them statistically. Under these circumstances, the Central Limit Theorem practically guarantees you a normal distribution. With that in hand, you can confidently and correctly model the process, as I have, and as Audette did earlier.

You may recall that I initally stated that the rifle had to be free of "special cause" (large, identifiable sources of error).

I have coached hundreds of industrial process projects, taming processes as diverse as molding steering wheels and reducing error in sales forecasts. We use these principles routinely, day in and day out, and they routinely conquer the problem. Rifles are no exception. In fact, rifles are a prime example.

If you choose to believe otherwise, that's fine with me... I feel no need to change your point of view. But what I have published is grounded in good physics and solid math, not opinion.

quote:

Then you missed the whole point of statistics.

Hey, I feel the same towards you. I'm sure you were taught in a little different fassion.

quote:

If you choose to believe otherwise, that's fine with me... I feel no need to change your point of view. But what I have published is grounded in good physics and solid math, not opinion.

We apparently have a difference in what we believe the definition of Factual Evidence or simply a Fact.

I don't question your Mathmatical approach in any manner Denton but, what you are doing is simply creating Theory. That theory has developed a strong opinion on your behalf, I'm by no means trying to change your opinion and do feel this discussion got alittle to in depth for the original question at hand.

Statistics is by no means true in any manner due to so many varibles in different problems but, we clearly do don't agree on Statistical Standpoints either.

I'll stick w/ my 3 shot grouping theory and you stick w/ your 5 shot theory . At least we'll have a blast doing it.

Have a good one.

Reloader

quote:

what you are doing is simply creating Theory

No.

What I am doing is applying an old, well-proved, reliable, general theory and model to a specific situation.

quote:

Then you missed the whole point of statistics.

When you have a few large variables, such as barrel rub, and shooter flinch, you treat them individually.

This in fact is where I disagree with the application of a larger statistical group. It's the large variable that I am indeed trying to avoid with my factory sporters. The problem with some of them is that indeed they will not shoot good five shot groups due to barrel heating.

I would shoot larger groups than three shots if that variable was not haunting the practical application.

"If scientific reasoning were limited to the logical processes of arithmetic, we should not get very far in our understanding of the physical world. One might as well attempt to grasp the game of poker entirely by the use of the mathematics of probability."
Vannevar Bush
US electrical engineer (1890 - 1974)

quote:

It's the large variable that I am indeed trying to avoid with my factory sporters.

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!

Harold Vaughn had a really good section on thermal fliers in his book. He claimed that it is hard to make a really rigid threaded joint, such as barrel to receiver. He went to an unusual thread profile that spreads the load more evenly, and makes a more rigid joint. He said it cured thermal fliers in his rifle.

Easy cure for thermal fliers: patience!

Let the barrel cool betweel shots. Then you have a 5 shot group of 5 cold (relatively speaking) shots.

Take several guns to the range and alternate them. I gets lots of practice with my .22's while waiting for the centerfire's to cool. Besides, it's fun you know!