Number of shots to establish zero

[JR1200W3]

Don't see how this adds to the discussion tbh, especially since you only seem interested in questioning the utility of knowing how solid one's zero is.

Anyway, Hornady just published an excellent new podcast episode yesterday titled "Is Your Zero Wandering?" and I would highly recommend it to anyone reading this thread.

It would speak to your desired end state. Are you trying to solve a real problem that exists in the conduct of an overall action or event? It would also potentially describe your experience as a shooter. Which could indicate how much to trust your assessment of the problem.

Statistics in support of a practical application? Or the static range plinking is the medium for your ultimate endstate: operationalizing statistics for the sake of geeking out?

Your reluctance to expound tells the tale

 

[lash]

Don't see how this adds to the discussion tbh, especially since you only seem interested in questioning the utility of knowing how solid one's zero is.

Anyway, Hornady just published an excellent new podcast episode yesterday titled "Is Your Zero Wandering?" and I would highly recommend it to anyone reading this thread.

My zero doesn’t wander. It is happy where it is now. It gets all the food, water, a dry bed and good company that it needs right here.

 

[stats_guy]

Are you trying to solve a real problem that exists in the conduct of an overall action or event?

Well of course it's solving a real problem - wouldn't you agree that all else being equal, someone who knows they have a rock solid zero has at least a little bit of advantage in a competition setting over someone chasing their zero all over the target?

Your reluctance to expound tells the tale

I simply lost interest in engaging when I felt that you were not asking in good faith and wanted to turn it into some weird argument from authority, as you make it clear:

It would also potentially describe your experience as a shooter. Which could indicate how much to trust your assessment of the problem.

It's actually a pretty simple concept and the Hornady dudes do a much better job explaining than I could - I would also say they are a pretty good authority so maybe you would trust their assessment of the problem

 

[JR1200W3]

Well of course it's solving a real problem - wouldn't you agree that all else being equal, someone who knows they have a rock solid zero has at least a little bit of advantage in a competition setting over someone chasing their zero all over the target?

I don't think, what you think is the problem, is the problem. Mechanically your zero is your zero. The factors that change your zero are most often shooter induced. And of the shooter induced causes, positional influence is #1. And the solution to that problem isn't shooting a shit ton of rounds from 1 position. If it's a positional issue, the solution is introducing an aggregate of zeros from multiple positions. Shooting more rounds from an unrealistic bench position doesn't solve the most common and impactful problem.

This is exactly the gap in understanding a stats guy would have vs an experienced shooter. Hence why I asked that question. My wife has a PHD in molecular biology and is pretty skilled in stats, has conducted clinical research for years. She now works for a medical device company that has a stats team. She works as medical science liaison, working with doctors to help them publish their groundbreaking procedures with her company's devices. She's constantly going to battle with the boneheads in the stats department because they don't understand the reality of application. It's a stats guy problem. Lost in their silo.

I shot two 5rd groups before the last match I shot. One prone, one off a barricade. The day prior. Didn't change anything, didn't check zero the morning of the match, won the match. Make your app, doubt anyone but the uninformed will care.

 

[stats_guy]

Mechanically your zero is your zero. The factors that change your zero are most often shooter induced. And of the shooter induced causes, positional influence is #1.

I think this is where we disagree. You are not finding your exact mechanical zero (the true center of the cone of dispersion) with a 5 shot group, and the shift in POI you attribute to positional changes is likely random variation in the mean POI that any two 5 shot groups are likely to have. I have not personally seen a repeatable and significant POI shift from positional changes.

Ledzep's chart shows us that even with a pretty precise rifle and load setup, there's a decent chance the center of any given 5-round group will be off by 1/4 MOA or more from the true zero, and my app says the same thing. This is 200 year old settled math, and not a topic worth arguing about.

Of course using your zeroing technique won't stop you from winning a match, in the end it's a relatively small variable in the grand scheme of things. I'm sure you have a very precise rifle and the shooting skills to go with it. But all else being equal, having a better, lower uncertainty zero is still undeniably a real advantage.

Here is an example of two 5 shot groups to further illustrate this. My app can also compare groups, and one of the results is it tells you the likelihood of there being a real difference in POI between the groups being compared. These two groups (blue and green) are similar in precision, and the centers are .22" apart. But the analysis shows that this apparent shift is very likely just due to random variation. This is another example of the kind of real utility statistics can have - if I shot that green group after zeroing to the blue group, instead of adjusting my elevation up a tenth, I'd make a combined 10-shot group out of it and zero to that.

 

[6.5SH]

Looks neat, but I'll also ask, what disciplines do you shoot and how often?

 

[stats_guy]

PRS/PRS-style shooting with a 6 ARC and a 223 bolt gun, usually shooting steel to 600 yds, occasionally 1000 yds. I've competed in a few regional matches and in more informal club matches. I shoot once or twice a month, sometimes more frequent.

Doesn't have a bearing on the topic at hand though - the basic idea applies to every kind of discipline and experience level.

 

[6.5SH]

PRS/PRS-style shooting with a 6 ARC and a 223 bolt gun, usually shooting steel to 600 yds, occasionally 1000 yds. I've competed in a few regional matches and in more informal club matches. I shoot once or twice a month, sometimes more frequent.

Doesn't have a bearing on the topic at hand though - the basic idea applies to every kind of discipline and experience level.

Thank you for answering. It does have a bearing because your prior responses came off as someone who didn't actually shoot or compete.
I'm sorry if that comes off as sounding harsh, but there was a similar thread and an app that ended up being a reskin of another member's paid app.

 

[stats_guy]

Not harsh at all and thanks for that info - I wasn't aware of that other thread. I realize I probably came off as someone who is only interested in the math since that's all I've been talking about..

I do actually care about the sport, and my goal with this app is to put useful statistics in an easy to use package with approachable, intuitive results, which I believe can help shooters in any precision-oriented discipline.

 

[JR1200W3]

I think this is where we disagree. You are not finding your exact mechanical zero (the true center of the cone of dispersion) with a 5 shot group, and the shift in POI you attribute to positional changes is likely random variation in the mean POI that any two 5 shot groups are likely to have. I have not personally seen a repeatable and significant POI shift from positional changes.

This is a very stats guy thing to say. You see variation and you confirm your stats background bias. That variation just exists and the law of large numbers is the only way to resolve clarity. I think one of the mistakes that stats people make is just accepting differences as unresolvable natural variation. I think that with quality equipment and skill some of these differences are actually controllable. And that the natural uncontrollable variation is smaller than you think. Because you're not exploring ways to progress and affect it. Your mindset is that it is what it is and the way to deal with it is just statistical analysis to see through large variation to make the best estimate possible.

The fact that you haven't seen examples that support my assertion and you have already come to the assumption that what I think is a positional difference and thus controllable, is just random variation is the bias you have. Also, the fact that you haven't explored positional influences demonstrates to me your fluency in marksmanship fundamentals and experience level.

Ledzep's chart shows us that even with a pretty precise rifle and load setup, there's a decent chance the center of any given 5-round group will be off by 1/4 MOA or more from the true zero, and my app says the same thing. This is 200 year old settled math, and not a topic worth arguing about.

Of course using your zeroing technique won't stop you from winning a match, in the end it's a relatively small variable in the grand scheme of things. I'm sure you have a very precise rifle and the shooting skills to go with it. But all else being equal, having a better, lower uncertainty zero is still undeniably a real advantage.

Here is an example of two 5 shot groups to further illustrate this. My app can also compare groups, and one of the results is it tells you the likelihood of there being a real difference in POI between the groups being compared. These two groups (blue and green) are similar in precision, and the centers are .22" apart. But the analysis shows that this apparent shift is very likely just due to random variation. This is another example of the kind of real utility statistics can have - if I shot that green group after zeroing to the blue group, instead of adjusting my elevation up a tenth, I'd make a combined 10-shot group out of it and zero to that.

And here is the stats guy mindset again. You think you're onto something meaningful by identifying .22" or 1/4moa center to center differences. With a scope that can only resolve .36" differences. While overlaying positional influences to further murky the waters. This is the stats guy disconnecting from reality and finding statistical significance that isn't meaningful or significant in the reality of application. I'm not disagreeing that your app and a larger shot group could help refine a true POI. What I'm disagreeing with is that it's meaningful and where a shooters focus needs to be. With the limitation of time, money, and focus....is nancing about over .2" POI uncertainty the best place to prioritize? To me.... this is where I see newer shooters make very common mistakes. Misappropriating importance on things that don't actually contribute meaningfully. A shooter is far better off focusing on how he drives the gun than wringing their hands over one click this way or that way.

I don't think a humans ability to approximate the center of a shot group pattern is a difference maker.

Now maybe if you go back and reread my previous posts you'll see them differently. I perceive that you think I disagree with your premise and you continued to plead your case. Think about it differently. Is there a real requirement for what this app will provide? Not, is a zero worth having.

 

[JR1200W3]

It sounds like you're new to the concept of positional testing. It is more prevalent in precision ARs due to barrel nut deflection. I'm this case, in addition to raw shooters positional influence, you also have to contend with mechanical impacts to your POI due to different positions.

Are all of these POI shifts due to random variation of a larger aggregate shot group?

And here's a positional test with a bolt gun. I shot this to contrast the trend seen with gas guns. Similarities? Differences?

And here's the RD LPR-15 (second photo above) shooting a 6x5 in the prone. No positional. Contrast this with the positional test.

Question 1: What do you think is the exact POI uncertainty in the above two photos? The 6BR and the prone 6x5.

Question 2: Is that amount of uncertainty impactful? If so, explain how?

Question 3: Based on the observed POI differences in the positional tests, what's more impactful? POI uncertainty due to too few shots in a group? Or POI shifts from positional influence?

 

[carbonbased]

A shooter is far better off focusing on how he drives the gun than wringing their hands over one click this way or that way.

This is what I’ve found in my marksmanship journey.

If someone made an app that analyzed one’s shooting fundamentals…now that would be interesting.

For now we have attending classes with good instructors, having a knowledgeable friend, YT vids, and filming yourself shooting. And practice. Lots of practice.

 

[JR1200W3]

And here's another aspect of zero'ing that I think is more meaningful than resolving .2" of POI uncertainty.

When able, I zero at 300yds. I use a 100yd zero ballistically but I dial on 300yd data and physically zero my 300yd data at 300yds. In reality, I kind.of don't really give a shit where I'm at at 100yds. I care that my trajectory is anchored at 300yds and 1000yds. At 300yds one click on an mrad configured scope is 1.08". You can very easily identify a difference in POI vs POA at this distance and, within the resolution of your scopes adjustment, marry those two as close as possible. 100yds reduces the resolution to the level of minutae that your attempting to resolve with your app. Where as, a person can just zero at 300yds and see very easily. We don't shoot 100yd targets in PRS but we will shoot very small targets at 300. WHERE is it more important that your POI is resolved?