Advanced Marksmanship The Measure of a Man and His Rifle

[2aBaC̶a̶]

How can you measure something if there is no standard?

I feel like a 3-5 shot group simply qualifies the shooter and rifle to be further measured with a more in depth test. If a shooter or the rifle cant even print a decent group at 100yds is there a point in shooting more? A 20 shot group further qualifies but goes into actually testing on a scale. At what point does a persons fundamentals or lack of start to inluence the group size?

It basically breaks down into why, what, how, where...

The why... what information are you hoping to get out of it? Whats being tested?
The what... What target are you shooting?
The how... How are you shooting it? 5 shots? 20? All at once, round robin, one shot off the rifle?
The where... prone, standing, of an obstacle, tripod?

Whats the standard?

 

[Lowlight]

That is the point, they were saying any standard needs to follow the rules of statistics, as in, more is better.

They want a number of statistical significance if you are making claims in terms of accuracy or precision, unfortunately, the shooting world never operated like that.

This what happens when guys write articles that state everything we do today (in other words, as a standard practice) is insignificant when it comes to how we look at things. Whether reloading or shooting groups, while the standard practice was for 100 yards where 3 for the rifle, 5 for the shooter, now they want 20 at 200... because of numbers.

We get it, 10 is a better measure than 5, and 20 is a better measure than 10, but at what point do we say, enough is enough?

 

[phlegethon]

This what happens when guys write articles that state everything we do today (in other words, as a standard practice) is insignificant when it comes to how we look at things.

Everything in Cal’s article was correct. We can’t reject the truth just because we don’t like it.

We get it, 10 is a better measure than 5, and 20 is a better measure than 10, but at what point do we say, enough is enough?

That depends on the dispersion in the data, and how sure you want to be. The lesson of statistics is not “more is always better.” It’s that there is a sample size that is enough, and less than that isn’t.

 

[2aBaC̶a̶]

Yeah, 20 is a better number(statistically)

Is it fair to say, a poor shooter could shoot a 1/2" 3 shot group with a good rifle.
An exellent shooter wont shoot a 1/2" 3 shot group with a bad rifle.

So to qualify a rifle, it doesnt take much.

And If they keep going at a certain point that poor shooter will pull a shots and his group will open up to his average.
An excellent shooter might be able to hold 1/2" for 10 shots or more before it opens up to his average.

At a certain point its diminishing returns. They're both going to achive an ES and SD. And at the same time the more shots taken other factors start to influence the outcome. Ammo varience. Fatigue. Barrel. Everything has an SD and ES. Like stacking tolerances.

Whats that number? Is 20 enough?

We would actually have to test at what point it is statistically enough.

I dont think 5 is enough.

 

[Lowlight]

Everything in Cal’s article was correct. We can’t reject the truth just because we don’t like it.


That depends on the dispersion in the data, and how sure you want to be. The lesson of statistics is not “more is always better.” It’s that there is a sample size that is enough, and less than that isn’t.

Didn't say he wasn't correct,

Just saying he is trying to rewrite history by pointing out that our values are statistically insignificant

Most of it was in regards to reloading, which I get, some people enjoy and want to push it to the edges, but the problem is, it spills over into everything because want to apply his work to EVERYTHING

It's not about not liking the TRUTH it's about reality, what can you realistically get people to follow

If I come up with a hair-brained plan to require everyone who posts on this site to only post 10 Shot groups, great. Now enforce it

 

[ma smith]

We get it, 10 is a better measure than 5, and 20 is a better measure than 10, but at what point do we say, enough is enough?

I think its fine to use small partition sizes, there is a reason this is done...the whole 3 test the rifle, 5 test the shooter is about partitioning....and its fine.

The point about partitioning is that there is usually a reason behind the partition...We should think about what those reasons are, critically evaluate tests that way. Its not true that "more bigger" = better.

Becaue maybe 1x extra group is valuable. That extra parition mabe better contribution in terms of signa/noise (information content) than "larger sample size" is to the analysis,

 

[Lowlight]

I agree to the point people won't follow something

In a way, we are trying to get people to do something different ... that is the bottom line. That difference is to shoot more to demonstrate the capabilities of the rifle, and really, the shooter, as we are not detaching one from the other.

This my point about the statistics, we have a standard practice of 3 to 5 shots. We all know what this means to us when we see it. Now we have an article, 3 part, that talks statistics, and there is nothing wrong with it, until, people leave the PRB Safe space and start demanding others follow along, which is what happened.

Then we start seeing all these micro conversations about sample size and group size and what the sample size and group size mean. Sure the math is solid, but the process is what is flawed. Nobody argues the math, done, sold. However we have to look at Human Nature, and Cal likes to come off definitive. When people read his stuff and trust me, it's not always right, no reason to get into the wrong. But his charts and graphs and general well laid out articles convince people, do this or else. I can't say if that is good or bad, but I tend to see the bad side of it.

In no way do I have an issue with any individual who wants to shoot more because they want to fall into the statically significant category. However, when people start endless arguments that the numbers are too small, fuck off.

And really if this just fell into the reloading side of the house I would never mention it. I have no issue with people who reload pushing the envelope to confirm their data. Sure I hate the Anal Retentive Reloading who can't do anything because he is still "developing" his load. If you talk on the internet about how great you do it, then when called out you can't because of more work to be done, you crossed the line. But if you are a productive shooter who happens to be an anal-retentive reloader, good on ya, I get it.

That is all, it's about Context and not issue blanket statements, it's about what you are trying to do by repeating the statistics of things. If you call someone out because they shot 3 round group, you need help.

Our ancestors knew statistics, they know best practices and choose to boil it down to 3 or 5, some people want to take it further to 10 or 20, great. Mind your own business, shoot 20, and leave everyone else alone.

 

[2aBaC̶a̶]

Ironic that all of it boils down to can you pull your rifle out at any given time and hit the target.

1 shot.

 

[Lowlight]

That really is the goal,

1 shot 1 kill

 

[Rocketvapor]

Drag the rifle out of the safe, drive to the range, pop off a CCB shot, 1/2 MOA, pack up and drive home.
Rinse repeat. What fun is that?

 

[ma smith]

Ironic that all of it boils down to can you pull your rifle out at any given time and hit the target.

1 shot.

Exactly

 

[Lowlight]

I often carried a separate target for that, and then not go home

I think as Cory mentioned, stacking rounds over time is a better measure, we need a target that travels better than traditional paper.

Steel is too forgiving, so something like a syntec paper target which can be shot over time

 

[Rocketvapor]

I use a superzoom camera for out to 300 yards. Can record the order of my shots.
Good groups on splatter targets go on the fridge
Steel is for impressing others on the line. Ding, ding, etc.

 

[2aBaC̶a̶]

I often carried a separate target for that, and then not go home

I think as Cory mentioned, stacking rounds over time is a better measure, we need a target that travels better than traditional paper.

Steel is too forgiving, so something like a syntec paper target which can be shot over time

how about standardized target anyone could shoot and then scan into an app that would composite overlay them as layers. A digital version.

 

[Rocketvapor]

Cold Bore Plus a 5 shot group. If you are good go out past 100yds.
I not be good.
Take it home and then back to the range and shoot another row.
Glue the sheet to a backer board.
Avoid the desire to keep shooting. A trip, one row.
I might try this my next trip.

 

[Lowlight]

how about standardized target anyone could shoot and then scan into an app that would composite overlay them as layers. A digital version.

That would be worth talking to Ballistic X about

Would be pretty smart really, creating an overlay with a reference point

 

[6.5SH]

I often carried a separate target for that, and then not go home

I think as Cory mentioned, stacking rounds over time is a better measure, we need a target that travels better than traditional paper.

Steel is too forgiving, so something like a syntec paper target which can be shot over time

One of those thin foam core yard sale signs with the target printed on them would be pretty durable.

 

[Lowlight]

I can leave cardboard at the range and just pull it out,

the yard signs are okay but they have to painted or covered,

I am just saying not everyone has a range, I can leave stuff behind

 

[Rocketvapor]

And
Measure group from center.
Not like those 5 shot groups that are 3 inches right and four inches down.
But
I guess 5 shots in the liver would still hurt

 

[Lowlight]

Or the Spleen if they pulled it the other way

 

[Deleted member 113831]

... we need a target that travels better than traditional paper.

Steel is too forgiving, so something like a syntec paper target which can be shot over time

I live in the Pacific Northwest right up on the border north of Seattle. It rains over 180 days a year here sometimes, so if I want to get any shooting in I have to use a waterproof target.

I use Tyvek. It is a fucking fantastic target material. It is flexible, strong, not expensive and absolutely waterproof.

Put an orange dot on it and cover it with clear packing tape and it will withstand a day long downpour. You can shake it off, three-hole punch it and put it in a binder for next time.

 

[ma smith]

I use Tyvek. It is a fucking fantastic target material. It is flexible, strong, not expensive and absolutely waterproof.

+1

 

[357Max]

After reading this whole thread. I think the craft data target is a better measure of a man and his rifle then any 10 or 20 from a bench or prone.

It actually measures both the man and his rifle. Hell I learned more from 3 craft targets (1 per gun), then I've learned from any 5 x 5 etc.
And broken down the craft is only 3 shot groups per position.

I was struggling with an AR308 that wouldn't group better then 2-1/2" bi-pod, bag, & bench. Fucked around for about 100 rounds trying different ammo ect. After installing a new scope and barrel the first 5 rounds both zeroed the scope & told me all I needed to know about it's potential.
Every 5x after confirmed what I learned in that first 5, but didn't teach me a whole lot more.

The first 12 round craft target showed me what both I as a shooter lacked & revealed what could be improved on the gun.
The 4 positions used will carry over to both hunting and match type shooting so yeah I'm a Craft fan boy now!

I think you could use the craft to accurately qualify/classify shooters for a match. Get X score in 2 min = X class, get same score in 90 sec +1 class etc.
Problem is you'd have a bunch of fuck stick's sand bagging the test to win in lower class!

It's really impossible to set a std with so many variables in purpose, gun, optic, support, trigger etc etc.

Like any data the useful info is directly dependent on ones ability to understand what it's telling you.

In my fields of expertise the less someone knows the more info they request & they don't understand what the fuck their looking at!
If they did they wouldn't need it.

 

[Davo308]

This is like the difference between a hunter and a bench rest shooter.

 

[Mike Casselton]

I want to hear more about this Spin Drift @ 100 yds.
Sounds like an excuse I could use

This is Spin Drift at 300mm.
Note the heavy rotation in the center that causes drift from the LOS..

 

[Rocketvapor]

This is like the difference between a hunter and a bench rest shooter.

Or a good blood tracker and a Squad Sniper

Measure a Cold Shot or a Group as the max distance from POA.
Some BR shooters shoot for score, not group size.

 

[pmclaine]

You need to dial out your spin drift, cause all those right side impacts have to be spin

The top row is a black circle can you not "Quarter" the target ?

This actually points to a lot of problems just in what you are saying

but left hand gain twist

 

[phlegethon]

Or a good blood tracker and a Squad Sniper

Measure a Cold Shot or a Group as the max distance from POA.
Some BR shooters shoot for score, not group size.

Yes, there are many different disciplines with different goals. One of the problems with this discussion is that you can’t have a single standard that is relevant to everything. You have to focus on what the goal is.

That being said, I can’t think of any shooting discipline where the extreme spread of a cherry picked three or five shot group is going to be a good standard, and that seems to be what everyone on the internet loves. Personally, I’m interested in the size of my cone of fire in each position, because that’s going to tell me what size target I can reliably hit. I love @JUSTIN amateur’s whole box at 100 yards challenge, both because it really gets you in the zone and shows you when your fundamentals are sound, and because it graphically shows you your circular error probable.

 

[Leftie]

Yes, there are many different disciplines with different goals. One of the problems with this discussion is that you can’t have a single standard that is relevant to everything. You have to focus on what the goal is.

That being said, I can’t think of any shooting discipline where the extreme spread of a cherry picked three or five shot group is going to be a good standard, and that seems to be what everyone on the internet loves. Personally, I’m interested in the size of my cone of fire in each position, because that’s going to tell me what size target I can reliably hit.

I think that, pragmatically, this is an issue: the more complex or specialized the task is that you seek to measure, the more narrowly defined the parameters of the testing criteria must be, and the less generally they can be applied towards similar tasks. I agree with @phlegethon in that you have to focus on what the goal is, but also stand firmly behind your rationale for the criteria, and not give in to criticism that your standard is wrong. Standards are entirely relative to their context.

Why is this important? Because the application of the concept is contextual as well. As others have said on here, there are guys who measure their progression by group size from a bench at X number of yards, and then there are guys who measure their progression by being able to place one shot inside a designated-size target at X number of yards from a variety of different positions, etc. There are nearly endless variations to this that can include different criteria, but the rationalization of the standard that you choose to follow (or are required to adhere to) comes from relative context/contexts that you choose to include as relevant, and also comes from you choosing to define the contexts/disciplines that do not fall within what you choose to justify as relevant.

To a degree, I think that the subject of having one target that can be shot/scored different ways dependent on the context makes more sense than having one criteria to ultimately tell someone that they are "accurate" or not. I do think that, in any measurement, the opportunity to show repeatability is important, because it allows you to diagnose errors across similar -if not identical- scenarios. This is one reason why I really like "dot torture" targets for pistol shooting, which is kind of what the current target design reminds me of in a good way.

 

[1moaoff]

4x5 is 1 box of ammo for factory guys so I'm good with that as a baseline

Then if you want bragging rights or a LL pat on the back he can up the game

 

[Baron23]

Steel is too forgiving, so something like a syntec paper target which can be shot over time

Maybe mylar sheets or rolls. Comes clear, in colors, or frosted/milky.

Just a thought

 

[_Raining]

An exellent shooter wont shoot a 1/2" 3 shot group with a bad rifle.

The whole point of the argument that 3 shots isn't enough is that you can get lucky and shoot very small 3 shot groups with a shitty rifle. You can shoot small 10 shot groups with a shitty rifle, it is just way less likely to happen compared to a 3 shot group.

The entire point of this thread is to discuss how much is enough. There is no debating the math. The debate is when it is all said and done and you have a % confidence of "is load A better than load B" or "is John better than Joe", are you OK with that %?

The problem is people just don't seem to understand that the % for a sample size of 3 is crazy fucking low in most cases. But it isn't as simple as JUST sample size though. If John has a 3 shot group of .1 MOA and Joe has a 3 shot group of 20 MOA, then the confidence % that John is better than Joe is much higher than if it was .5 MOA vs .55 MOA.

If you were recruiting a pitcher for your college team, would you be OK with having 20 different high school pitchers throw 3 pitches each? I wouldn't be OK with that. But because we need to pony up the cost of the wear and tear of the barrel and cost of the ammo, we all of a sudden accept 3 shots as acceptable. In the end, it doesn't matter how many likes your .2 MOA 3 shot group gets on facebook, it doesn't guarantee you will win an F Class or PRS competition. You are just doing yourself a disservice by not getting a sample size that better evaluates how well you (or your load or your rifle etc) will do.

The point of a valid standard would be so people could do things like see what all the Bergaras and Tikkas were scoring, or what are the best shooters on the hide are scoring and compare yourself to them or to track your own progress over time. That 25 dot drill is going to provide more meaningful data than if it was just people posting 3 shot groups.

 

[Lowlight]

How come we don't see more .25" 3 shot groups, people always manage to toss one if they are not capable

 

[ma smith]

3x into 6,4 mm hole from a 6,5 round isn't gonna happen by luck

 

[2aBaC̶a̶]

The whole point of the argument that 3 shots isn't enough is that you can get lucky and shoot very small 3 shot groups with a shitty rifle. You can shoot small 10 shot groups with a shitty rifle, it is just way less likely to happen compared to a 3 shot group.

The entire point of this thread is to discuss how much is enough. There is no debating the math. The debate is when it is all said and done and you have a % confidence of "is load A better than load B" or "is John better than Joe", are you OK with that %?

The problem is people just don't seem to understand that the % for a sample size of 3 is crazy fucking low in most cases. But it isn't as simple as JUST sample size though. If John has a 3 shot group of .1 MOA and Joe has a 3 shot group of 20 MOA, then the confidence % that John is better than Joe is much higher than if it was .5 MOA vs .55 MOA.

If you were recruiting a pitcher for your college team, would you be OK with having 20 different high school pitchers throw 3 pitches each? I wouldn't be OK with that. But because we need to pony up the cost of the wear and tear of the barrel and cost of the ammo, we all of a sudden accept 3 shots as acceptable. In the end, it doesn't matter how many likes your .2 MOA 3 shot group gets on facebook, it doesn't guarantee you will win an F Class or PRS competition. You are just doing yourself a disservice by not getting a sample size that better evaluates how well you (or your load or your rifle etc) will do.

The point of a valid standard would be so people could do things like see what all the Bergaras and Tikkas were scoring, or what are the best shooters on the hide are scoring and compare yourself to them or to track your own progress over time. That 25 dot drill is going to provide more meaningful data than if it was just people posting 3 shot groups.

Potato

 

[furlmart]

I like “Know your limits” style target for training with a focus on first round hits.

Attached is a target with 7 circles with diameter 60, 50, 40, 30, 20, 15, 10 mm. All are simple orange circles to enable you to spot your hits through the scope.

My course of fire is starting with the largest and move to the next after placing a hit. After every hit, before moving to next target, I break my position and build it new. After 3 failures in a row on the same target I stop shooting.
My measure of capability is the size of the smallest target I can hit consistently in a row of first round hits.
The rule to allow to continue after a failure is just to avoid too much of frustration.

Obviously, the largest circles are not challenging when shooting prone. But this target is used also for positional and unsupported shooting.

 

[Ledzep]

Just found this thread. Looks like I'll be up a while tonight

About a year ago I started reflecting on load development. I took a look around at what a person can buy and do and thought to myself that it should be easy enough to isolate variables to at least get an impression of what matters and what doesn't. In my mind there should not be a decades long argument over whether to start with seating depth tests, or OCW, or powder ladder tests, or Satterlee tests.... Certainly there is a way to (within the bounds of real life) isolate variables to begin to quantify the effects of changing powder charge, changing seating depth, SRP vs. LRP, Crown angles, barrel tuners, etc... etc... So little by little I've been working towards it. I'm not going to get into the entirety of the testing I've done so far, but the TLDR of it is that I've arrived at the conclusion (as it relates to this topic) that 20-35 shots of a single variable is sufficient to give the end user a pretty solid idea of what that set of conditions is going to do over the next several hundred (if not thousand) rounds of barrel life.

Why?

Because I have been exposed to probability and statistics. I'm not going to try to teach the subject, so the TLDR of it is that in order to use a standard deviation (SD), you assume that your sample follows a distribution pattern (usually "normal distribution", or a bell curve) AND most importantly that your sample accurately represents the population. This is huge.

Say for example, a 6.5 Creedmoor has a generally accepted 2500 round barrel life. Then our "population" is that entire 2500 rounds. Each variable we change (powder charge, seating depth, case mfg., powder type, etc.) then has a theoretical population of 2500 rounds. So if we could see into the future, we could set up load A, B, C, D, E, and F where we change 1 variable per letter. Then we imanginarily shoot 2500 rounds of A from a perfectly fixed barrel in a 1000yd indoor range and it produces a scatter plot on our 1000yd target. Then we reverse time, regain our barrel life, and try load B, then C, etc... Each produces it's own population scatter plot. And if we had a time machine and infinite supplies we could definitively tell which combination/arrangement of components would produce the tightest dispersion in that barrel... but we don't have those things.

So the age old battle has been trying to find the winning combination with as few rounds as possible because we don't have time machines to wash round counts off of our barrels. Unfortunately, what has developed out of this search is traditions that are skimpy on one of the best tools that are available to us, probability and statistics.

Every MFer out there with a chronograph has shot groups and collected velocities and been tickled pink when a tight spread over 5 shots gets produced. Myself included. When you scroll through that Chrono and it says "SD: 3" you're like "Oh yeah motherfucker.. that's right!". The problem is that most people don't understand the bounds in which SD is meaningful and useful.

I also don't want this to be a textbook on statistics. SD is ONLY RELEVANT IF THE SAMPLE REPRESENTS THE POPULATION. So then, how large must the sample be to accurately represent the population? Traditionally we've shot 3 and 5 shot groups. Is that good enough?

Say there's a campus of 2500 students and we nab 3 or 5 of them and question them about an upcoming election. Do we have a good idea of which way that campus is going to swing? Say we find a colony of 2500 ants and we capture 3 or 5 of them to measure for height/weight. Not seeing any other ants, do we have a good hold on how big ants from this colony are? Say we have 2500 rounds of useful barrel life with a given combination of reloading components and we randomly select 3 or 5 of them to test. Do we have a good feeling for how the other 2495-2497 will behave?

I submit "no". No we do not.

Why? Well after thinking about the above, I shoulder fired several variables at 50 shots per group (5x 10 shotters with cooling between, all with correlated POI/POA) and recorded the impact location and velocity for each shot. The first thing that I tested was a powder ladder test. The end results of the powder ladder test showed a negligible difference in ES/SD between all of the powder charges, and a nearly negligible difference in dispersion across the powder ladder. This caused me to look into the data a little more closely. Do I suck? Did I do something wrong? THERE WERE SUPPOSED TO BE NODES!

I plotted running averages, running SD's, running MPOI in horizontal and vertical directions. This basically showed the "total results by the round count". It was both fascinating and horrible. Fascinating because regardless of whether the first 5-10 shots showed an SD of 3 or 12, or 18, by the time it ended up at 50 shots, it was 10-12fps. All of my data (other than the avg. MV which obviously grew with increased charge weight) more or less converged. Horrible because it seemed to me that every single load development test I had done in the past was a complete and utter waste of time. To settle this in my mind I repeated the median charge test 2 more times and again had the results converged at my 50 shot mark. This rabbit hole has consumed thousands of rounds now and I have moved to an accuracy fixture to isolate the shooter out of the equation but that's another subject...

So why my remarks on 20-35 shots? Because for all intents and purposes, by 35 shots the tests were indistinguishable. The 15 following shots to get to 50 were insurance. In my opinion, 35 shots of a variable is enough to very accurately represent the population, and any statistical data derived from such a test is pretty viable for use in probability calculations. I can go more into depth on this subject if people want. Not surprisingly 30-35 is a fairly common 'rule of thumb' for sample size in use of statistics. I don't want to bore anyone. Every single shot represents a random event (to some extent), and it just so happens that the distribution of shots from a rifle tracks pretty close to a normal distribution relative to the MPOI. So you can plug in empirically derived SD's into an Excel spreadsheet with a random number generator for X and Y coordinates and produce realistic 1000, 2000, 100000 (whatever you want) shot groups, which can then be used with stuff like 4DoF to introduce other variables and have pretty useful hit probability info at the cost of 2 boxes of ammo.

Where does 20 come from? 20 is about the minimum mark where things are settled down with what I consider an acceptable level of error margin. SD's that will long-term average 11 will show up in 20 shot tests from 9-13fps. +/- 2fps. Who cares? If you apply 4 sigma or 6 sigma it's still not enough to matter in PRS/NRL match ranges, even the far targets. It's got enough resolution to tell you one load is better than another, one barrel is better than another, etc... without burning the extra 15-30 rounds to be 100% sure.

Why not 15 (or 10, or 7 or 5)??? Too much noise, IMO. I'd have to play with my data a bit to get you numbers for 10's or 15's but because 5's seem to be the "standard" I have played with them a lot and offer this example.

Say I shot a 1/2 MOA 20 shot group. We can expect then that pretty much every round of that load will be sub MOA for sure, probably better.

If I use that data to generate 5 shot groups, I will get groups that average in size about 0.37-0.42 MOA. BUT!!! I will get individual groups that are anywhere from about 0.15 MOA up to 0.85 MOA. Remember that part about randomly selecting 5 out of 2500? So when you shoot a ladder test with 5x of each load... How do you know if the 0.84 MOA group you just shot was representative of that load? You say "oh shit that wasn't good" because the groups right next to it were 0.2-0.4 MOA and you throw it away, never to be shot/tested again. Reality is that you fell victim to variance and small sample size.

A caveat on that last subject... There is a probability distribution going on so the odds are that most rounds are going to fall within X MOA for a given system. That's true.. You know like 70% of your rounds are going to fall within a pretty damn tight window... But 30% are going to fall outside of that window and it's random. You can prep your brass and weigh to the .00001gr and sort by this and by that.... low probability events still happen and the only way to know if what happened to you was a low probability event is to increase sample size.

Hopefully that makes sense. It's way past my bed time.

Another rabbit hole real quick:

Group size is a less than optimal way to measure dispersion. Whether you shoot 2 rounds or 2000 rounds, you are only using 2 rounds to qualify the group. I want to go to sleep now so maybe this will spark some discussion for tomorrow & the weekend, but mean radius is a much better metric. Alas it requires a bit more math to figure-- but a lot of these apps do it anyway and tell us and we ignore it or don't understand what it means.

So Frank, I understand I'm up against thousands and thousands of shooters set in their ways, and an industry with traditions that are what they are, but that doesn't mean that there aren't better ways. Not everyone needs a true 1/2 MOA all day long rifle+ammo combo, and not everyone needs to know that it is 1/2 MOA. However, a statistically significant method for comparison is desirable to sort out the white noise BS. The more we truly learn the more we can push the envelope. The more white noise BS we push around the slower we progress.

100% agree with THEIS about isolating what it is you want to test and testing for it appropriately. No two barrels, shooters, lots of bullets, etc. are the same. It is very difficult to say "Brand X model A shoots # mean radius at 200yd and Brand Y model B is 10% better".

Nonetheless, I am a fan of the dot drills, but IMO they should be the same size aiming point for all 20, perhaps with 'ghost rings' for different sizes (1/4, 1/2, 3/4, 1 MOA etc..).

 

[1moaoff]

Frank,

Because there are so many options to choose from and no one will probably fit everyone 100% here's a thought.

If we look at 2 or 3 or 4 options similar to what you have in the 5x5 or Kraft training thread where the targets are evaluated. Then look at them as a representation and see what actually defines the shooter,, gun,, ammo,, maybe not define but more identify a trend or similar.

Is it possible that it would take 2 or 3 different approaches that can be easily tested?

I'm sure if you or someone else set up a protocol you could get feedback and enough people to take interest. Hell when I have a free day im going to do the Kraft just to see.

ETA, basically 1 to test gun and ammo or separate them... and 1 to test shooter. To me the 2 need to be seperated.

 

[acudaowner]

 

[_Raining]

Just found this thread. Looks like I'll be up a while tonight

About a year ago I started reflecting on load development. I took a look around at what a person can buy and do and thought to myself that it should be easy enough to isolate variables to at least get an impression of what matters and what doesn't. In my mind there should not be a decades long argument over whether to start with seating depth tests, or OCW, or powder ladder tests, or Satterlee tests.... Certainly there is a way to (within the bounds of real life) isolate variables to begin to quantify the effects of changing powder charge, changing seating depth, SRP vs. LRP, Crown angles, barrel tuners, etc... etc... So little by little I've been working towards it. I'm not going to get into the entirety of the testing I've done so far, but the TLDR of it is that I've arrived at the conclusion (as it relates to this topic) that 20-35 shots of a single variable is sufficient to give the end user a pretty solid idea of what that set of conditions is going to do over the next several hundred (if not thousand) rounds of barrel life.

Why?

Because I have been exposed to probability and statistics. I'm not going to try to teach the subject, so the TLDR of it is that in order to use a standard deviation (SD), you assume that your sample follows a distribution pattern (usually "normal distribution", or a bell curve) AND most importantly that your sample accurately represents the population. This is huge.

Say for example, a 6.5 Creedmoor has a generally accepted 2500 round barrel life. Then our "population" is that entire 2500 rounds. Each variable we change (powder charge, seating depth, case mfg., powder type, etc.) then has a theoretical population of 2500 rounds. So if we could see into the future, we could set up load A, B, C, D, E, and F where we change 1 variable per letter. Then we imanginarily shoot 2500 rounds of A from a perfectly fixed barrel in a 1000yd indoor range and it produces a scatter plot on our 1000yd target. Then we reverse time, regain our barrel life, and try load B, then C, etc... Each produces it's own population scatter plot. And if we had a time machine and infinite supplies we could definitively tell which combination/arrangement of components would produce the tightest dispersion in that barrel... but we don't have those things.

So the age old battle has been trying to find the winning combination with as few rounds as possible because we don't have time machines to wash round counts off of our barrels. Unfortunately, what has developed out of this search is traditions that are skimpy on one of the best tools that are available to us, probability and statistics.

Every MFer out there with a chronograph has shot groups and collected velocities and been tickled pink when a tight spread over 5 shots gets produced. Myself included. When you scroll through that Chrono and it says "SD: 3" you're like "Oh yeah motherfucker.. that's right!". The problem is that most people don't understand the bounds in which SD is meaningful and useful.

I also don't want this to be a textbook on statistics. Suffice it to say, SD is ONLY RELEVANT IF THE SAMPLE REPRESENTS THE POPULATION. So then, how large must the sample be to accurately represent the population? Traditionally we've shot 3 and 5 shot groups. Is that good enough?

Say there's a campus of 2500 students and we nab 3 or 5 of them and question them about an upcoming election. Do we have a good idea of which way that campus is going to swing? Say we find a colony of 2500 ants and we capture 3 or 5 of them to measure for height/weight. Not seeing any other ants, do we have a good hold on how big ants from this colony are? Say we have 2500 rounds of useful barrel life with a given combination of reloading components and we randomly select 3 or 5 of them to test. Do we have a good feeling for how the other 2495-2497 will behave?

I submit "no". No we do not.

Why? Well after thinking about the above, I shoulder fired several variables at 50 shots per group (5x 10 shotters with cooling between, all with correlated POI/POA) and recorded the impact location and velocity for each shot. The first thing that I tested was a powder ladder test. The end results of the powder ladder test showed a negligible difference in ES/SD between all of the powder charges, and a nearly negligible difference in dispersion across the powder ladder. This caused me to look into the data a little more closely. Do I suck? Did I do something wrong? THERE WERE SUPPOSED TO BE NODES!

I plotted running averages, running SD's, running MPOI in horizontal and vertical directions. This basically showed the "total results by the round count". It was both fascinating and horrible. Fascinating because regardless of whether the first 5-10 shots showed an SD of 3 or 12, or 18, by the time it ended up at 50 shots, it was 10-12fps. All of my data (other than the avg. MV which obviously grew with increased charge weight) more or less converged. Horrible because it seemed to me that every single load development test I had done in the past was a complete and utter waste of time. To settle this in my mind I repeated the median charge test 2 more times and again had the results converged at my 50 shot mark. This rabbit hole has consumed thousands of rounds now and I have moved to an accuracy fixture to isolate the shooter out of the equation but that's another subject...

So why my remarks on 20-35 shots? Because for all intents and purposes, by 35 shots the tests were indistinguishable. The 15 following shots to get to 50 were insurance. In my opinion, 35 shots of a variable is enough to very accurately represent the population, and any statistical data derived from such a test is pretty viable for use in probability calculations. I can go more into depth on this subject if people want. Not surprisingly 30-35 is a fairly common 'rule of thumb' for sample size in use of statistics. I don't want to bore anyone. Suffice it to say that every single shot represents a random event (to some extent), and it just so happens that the distribution of shots from a rifle tracks pretty close to a normal distribution relative to the MPOI. So you can plug in empirically derived SD's into an Excel spreadsheet with a random number generator for X and Y coordinates and produce realistic 1000, 2000, 100000 (whatever you want) shot groups, which can then be used with stuff like 4DoF to introduce other variables and have pretty useful hit probability info at the cost of 2 boxes of ammo.

Where does 20 come from? 20 is about the minimum mark where things are settled down with what I consider an acceptable level of error margin. SD's that will long-term average 11 will show up in 20 shot tests from 9-13fps. +/- 2fps. Who cares? If you apply 4 sigma or 6 sigma it's still not enough to matter in PRS/NRL match ranges, even the far targets. It's got enough resolution to tell you one load is better than another, one barrel is better than another, etc... without burning the extra 15-30 rounds to be 100% sure.

Why not 15 (or 10, or 7 or 5)??? Too much noise, IMO. I'd have to play with my data a bit to get you numbers for 10's or 15's but because 5's seem to be the "standard" I have played with them a lot and offer this example.

Say I shot a 1/2 MOA 20 shot group. We can expect then that pretty much every round of that load will be sub MOA for sure, probably better.

If I use that data to generate 5 shot groups, I will get groups that average in size about 0.37-0.42 MOA. BUT!!! I will get individual groups that are anywhere from about 0.15 MOA up to 0.85 MOA. Remember that part about randomly selecting 5 out of 2500? So when you shoot a ladder test with 5x of each load... How do you know if the 0.84 MOA group you just shot was representative of that load? You say "oh shit that wasn't good" because the groups right next to it were 0.2-0.4 MOA and you throw it away, never to be shot/tested again. Reality is that you fell victim to variance and small sample size.

A caveat on that last subject... There is a probability distribution going on so the odds are that most rounds are going to fall within X MOA for a given system. That's true.. You know like 70% of your rounds are going to fall within a pretty damn tight window... But 30% are going to fall outside of that window and it's random. You can prep your brass and weigh to the .00001gr and sort by this and by that.... low probability events still happen and the only way to know if what happened to you was a low probability event is to increase sample size.

Hopefully that makes sense. It's way past my bed time.

Another rabbit hole real quick:

Group size is a less than optimal way to measure dispersion. Whether you shoot 2 rounds or 2000 rounds, you are only using 2 rounds to qualify the group. I want to go to sleep now so maybe this will spark some discussion for tomorrow & the weekend, but mean radius is a much better metric. Alas it requires a bit more math to figure-- but a lot of these apps do it anyway and tell us and we ignore it or don't understand what it means.

So Frank, I understand I'm up against thousands and thousands of shooters set in their ways, and an industry with traditions that are what they are, but that doesn't mean that there aren't better ways. Not everyone needs a true 1/2 MOA all day long rifle+ammo combo, and not everyone needs to know that it is 1/2 MOA. However, a statistically significant method for comparison is desirable to sort out the white noise BS. The more we truly learn the more we can push the envelope. The more white noise BS we push around the slower we progress.

100% agree with THEIS about isolating what it is you want to test and testing for it appropriately. No two barrels, shooters, lots of bullets, etc. are the same. It is very difficult to say "Brand X model A shoots # mean radius at 200yd and Brand Y model B is 10% better".

Nonetheless, I am a fan of the dot drills, but IMO they should be the same size aiming point for all 20, perhaps with 'ghost rings' for different sizes (1/4, 1/2, 3/4, 1 MOA etc..).

This is fake news. What you should do is shoot 5x3 shot groups. Cross out the outliers. Circle the best 3 shot group. Post it on the internet saying I can shoot .5 MOA all day, when I do my part. Profit.

JK.

But seriously, I feel like people either get it and understand the concepts behind probability and statistics or they think you are full of shit and the top BR shooters have been using 3 shots to shoot tiny groups at 1000 yards so there is no reason to change their ways. Trying to convince a 1 shot per charge weight velocity person or a 3 shot group size seating depth person that there is too much noise with a low sample size is like trying to convince someone to change political parties.

 

[Greg Langelius *]

This discussion, this..., is why I stopped getting myself wrapped around the axle about numbers.

It's like the old basic standard, 'minute of venison', or 'dead is dead'. My standard is that the target 'gets defeated'.

It doesn't depend on distance, position, number of shots, or any number based criteria. Aim at the target, shoot, and you can pretty well determine whether or not you got a reasonable hit.

Remember the Death Camp scene in Big Red One where Lee Marvin leans into frame, looks, and says, "Ya got 'em, Kid..."

A hit is inarguable, it either is or isn't a hit. The rest of this stuff is arguable.

Greg

 

[Ledzep]

If you want to quickly achieve practical accuracy that's going to be in the 0.7-1.2 MOA total cone of fire (probably average .35-.6 MOA 5 shot groups) ballpark and you don't really care beyond that... Find a powder that fits your cartridge (look in the reloading section for powders that are popular for your chambering), get a good barrel, get a good bullet, pick what velocity you want (powder charge), load and shoot. Don't waste time with 5 shot tests of this or that. Shoot a single 10 shot verifier and roll on. If it doesn't shoot, swap a component (I suggest powder or bullet) until it does. Maybe play with seating depth in gross adjustments (.020-.030 at a time). That's what I do for my match guns anymore. Don't waste barrel life on load dev. that doesn't mean anything. Every near-pointless 5 shot group is a barricade drill you could've done.

If you want to get serious about shooting the tightest cone of fire possible to edge out competition or for your own personal OCD, then ditch the 5 round tests because they're noisy and don't really tell you definitively anything. Even repeating multiple sets of 5 rounds and trying to correlate POI vs. POA introduces another chance of error. Start with large sample size and work your way through it. Pick a cartridge with forgiving barrel life. Don't throw out fliers that were not called. Don't lie to yourself.

A few trends:
Seating depth has "happy spots".
Milder charges have milder dispersion
Brass (prep, brand, etc.) and primers don't matter as much as you might think. Virgin cases with nothing more than a chamfer can achieve outstanding results.

Now to compare shooter vs. shooter you have to either use the same gear or make some assumptions that might not be 100% true but are very close by assuming the gear is the "same".

To do shooter vs. perfection, put the action in a fixture, shoot a large sample group, then put it back in the shooter's hands and shoot dots or a single group and see how the mean radius or group size varies.

There's a little bit of luck involved always. Can't get around it other than letting the averages work over many cycles/samples. Long term scores at matches, cumulative points race winners, etc... show who's got it down and who's lagging.

 

[308pirate]

I think some sort of target with progressively smaller dots with central aiming points and a grid is in order.

If we are testing both accuracy *and* precision.....and are looking at practical real life purpose. Shouldn’t we be testing the *entire* system? By that, I mean both the rifle/optic and the shooter.

If so, the ability to hit exactly what we want, on command should be measured. The animal (2 or 4 legged) or steel doesn’t give six shits from Sunday if you can shoot a .2 moa group today at 2 o’clock on the dot and tomorrow another .2 moa group at 7 o’clock.

What matters is you can put that bullet as close to humanly possible to that dot every single time

I propose a 100yd target that has 2moa circles with a T or cross in it. All the way down to a .moa dot. Keep the T in it until it’s no longer needed to have a center aiming point. The target also needs .1 mil grid. Light lines for the grid. Bold for the circles and T/cross.

2 moa
1.75
1.5
1.25
1
.75
.5
.25
.2
.1

A fresh range trip is started with a two target test. The first target (10 shots) is done without zero or warm up (assuming you had rifle zero’d previously) and you aim at the center and only center of each circle/dot. Don’t adjust for wind or your zero being off. 10 shots. 1 at each. You should be able to see a pattern and see where your zero really is. You can also use the grids to plot all 10 shots later. We are purely measuring:
A: the system/shooter’s zero
B: precision/accuracy of the system/shooter

The next target (10 shots) is done after you take the info from the first 10 and either tweak your zero or adjust if for some reason it’s super high wind and pushing you off .1 or so. The goal is now to use everything at your disposal to hit the center of the circles/dots. Hold off, dial turrets, etc. We are now testing

The ability of the shooter to use the information about his rifle/conditions/themselves to successfully engage a target.

That would be useful to me

 

[pmclaine]

Damn! Looks like.....Maybe UNQ....

Probably not the best equipment for this exercise but you run what you brung.

Ive been wanting to take this guy out and I wasnt changing for you pussies....

Top row was the only target reticle allowed good crosshair reference. I wanted to make a scope change but didnt dare.

Second row didnt provide me much reference but I could just use crosshairs.

Third row I held under 1 mil using first row as aim point. There is 1 mil exact between every other row. First row dots are mil dot sized at 100 yards.

Fourth row held 1 mil under using second row.

Fifth row held two mils under using mil dot in the first row target dot. Tried holding my scope correction by keeping a "bump" high and right - kind of like a snowman toppling over to the right.

When I left added 1/2 MOA up and 1/4 MOA right to scope.

Fun. Going to have to try with Billy Beroo.

 

[x2cross]

The first target (10 shots) is done without zero or warm up (assuming you had rifle zero’d previously) and you aim at the center and only center of each circle/dot.

This is why I prefer single shots on each circle/dot. Shows what the system that includes shooter is capable of when doing the only thing that matters. Putting bullet where you want.

Me and one of my friends always take a cold-bore shot at 200 first thing when we show up to the range. Always a fun competition to see who can get closest to the dot. 1

 

[dzander]

pretty humbling.
3rd row aimed the 4th circle twice.

shot thru a chronograph , all rounds just to see how consistent my loads

6.5cm 140 berger hybrids running 2750 fps.

after first 2 rows i should have walked away for 5 minutes.

row 5 i came up .1 mils, dialed

pretty happy with extreme spread velocity 34 fps , over 35 rounds i thought that was pretty decent.

32 degrees out , wind did pick up some around 3/4 row but i was jerking the gun for sure.
will repeat if i get warmer weather and rest between 10 shots. i'd like to have a target with diamonds and white centers.
i have a 1/8 minute dot SMR3 reticle. got to work on some fundamentals.
I'dl ike to shoot 25 dots / 1 target full a week and compare results.

 

[Doing my part]

New shooter, but engineer in commissioning nuclear waste handling equipment. $0.02 incoming... Bear with me, I am talking about test processes not shooting per se, so I hope I'm contributing here.

When we set out to commission some equipment we usually break it down into compartments which isolate well. Let's say I have some waste which needs to be moved, dried, packaged and stored. Rather than press the button and expect it to go end to end in one go, I'll set pass/fail criteria for each phase and test them individually. Then test interfaces between processes. The last thing before going live is to do the end to end test, again with clearly defined pass/fail criteria.

The progressive five targets look like a great test, but comes with some built in assumptions and limitations. This isn't necessarily a bad thing - it just needs to be clear what the objective of the test is, and to recognise how it applies to whatever other kind of shooting you do.

In terms of testing, it's neither end to end, nor completely isolated - if it were bench rest with standardised ammo, it would have fewer variables. If you were only allowed to shoot one dot per day it would have more variables. Its a nice way to see how the shooter/gun system works - It delivers data on single shot accuracy and consistency. I like it for giving a feel for how a shooter and rifle behave in a reasonably closed environment.

As an aside, interesting to see in the practical uses above that if the shooter shot the bottom row at the top row they all look like they would have been hits. Aim small, miss small?

(edit for more better language)

 

[supercorndogs]

Damn! Looks like.....Maybe UNQ....

View attachment 7522318

Probably not the best equipment for this exercise but you run what you brung.

Ive been wanting to take this guy out and I wasnt changing for you pussies....

View attachment 7522319

View attachment 7522320

View attachment 7522321

View attachment 7522322

View attachment 7522323

View attachment 7522324

Top row was the only target reticle allowed good crosshair reference. I wanted to make a scope change but didnt dare.

Second row didnt provide me much reference but I could just use crosshairs.

Third row I held under 1 mil using first row as aim point. There is 1 mil exact between every other row. First row dots are mil dot sized at 100 yards.

Fourth row held 1 mil under using second row.

Fifth row held two mils under using mil dot in the first row target dot. Tried holding my scope correction by keeping a "bump" high and right - kind of like a snowman toppling over to the right.

When I left added 1/2 MOA up and 1/4 MOA right to scope.

Fun. Going to have to try with Billy Beroo.

Did you draw those little lines by the bullet holes? It kind of looks like bullets getting ready to blow up.

 

[pmclaine]

Did you draw those little lines by the bullet holes? It kind of looks like bullets getting ready to blow up.

I think those are shadows.

The targets were printed on card stock.

Parts of the paper raised up and you are seeing shadow.

 

[JBoomhauer]

My first attempt. Lost focus on a few.