Analyze My Groups

[nm.otter]

Please keep in mInd that even a 20 shot group size of .75” vs 1” or 1.5” vs 2.0” is not a real difference.

Right -- validating small differences requires large sample sizes.

 

[Harvey_NW]

 

[solarshooter]

According soley to Litz and his one flawed experiment? And so he says it then those HOF'rs know jack then? If it's so easy and no tuning or tuners are required some of you guys would be a shoe in to go win it all at will.

Please explain how the test was flawed. The HOF guys are incredibly good shooters, make incredibly consistent ammo, put together the absolute best rifles, and shoot the most out of anyone. Not knocking them at all. I just credit their success to factors other than their ability to "tune".

This video is worth a watch, yet another thorough test with meaningful sample sizes and proper analysis, done by an F Class champ with top level equipment:

I still think he ends up reading the tea leaves a little too much near the end, but his data shows that there was no significant difference.

I will restate my original bold claim in a more accurate way: I have not seen any evidence, in my testing or any others, that small changes in seating depth or powder charge have an influence on precision. Instead, the null hypothesis, which is that there is no difference and random noise accounts for any observed differences, has been proven over and over again.

I keep hearing people say, in the same breath, that no test could ever be designed to conclusively answer whether tuning works, and that they are sure tuning works because benchrest shooters who shoot small groups like to do it. This is so irrational it makes my head hurt. I'm still waiting for ONE SINGLE REFERENCE to a test of small seating depth or powder charge tweaks done with >10rds per sample that demonstrates a statistically meaningful difference.

 

[Harvey_NW]

I'm still waiting for ONE SINGLE REFERENCE to a test of small seating depth or powder charge tweaks done with >10rds per sample that demonstrates a statistically meaningful difference.

Caveat - they do say in some cases a lower powder charge can produce measurably less dispersion, if it's worth the sacrifice in velocity. Which I'm sure some would identify as a "node", but the ballisticians do acknowledge it.

For the most part, when using high quality components and temp stable single base extruded powders, I don't think it matters much.

 

[mxgsfmdpx]

Also, remember that we’re discussing hunting rifles here, not comp rifles. A 1.5” 10 shot group at 100 is larger than I’d like, but if I can squeeze that down to 1” for a 10 shot group, gives me the warm and fuzzy

Double the weight of your gun and I’ll bet your stringing tightens up (assuming your fundamentals are solid). “Comp guns” gets tossed around like they are some sort of unicorn guns when they really aren’t.

Stringing in your original posts points to potential for slight erratic shooter inputs/rifle movement during the process. Could be the shooting system or the shooter there.

Also, the amount of shooters who can lay down and actually put 10 bullets into a 1” dot at 100 every time is much rarer than you think, despite everyone on the internet somehow being able to do it.

If you are consistently shooting 1.5” groups of 10 shot from a hunting gun, just go shoot more and watch the hits at range come.

 

[Schmo]

Double the weight of your gun and I’ll bet your stringing tightens up (assuming your fundamentals are solid). “Comp guns” gets tossed around like they are some sort of unicorn guns when they really aren’t.

Stringing in your original posts points to potential for slight erratic shooter inputs/rifle movement during the process. Could be the shooting system or the shooter there.

Also, the amount of shooters who can lay down and actually put 10 bullets into a 1” dot at 100 every time is much rarer than you think, despite everyone on the internet somehow being able to do it.

If you are consistently shooting 1.5” groups of 10 shot from a hunting gun, just go shoot more and watch the hits at range come.

That’s basically what I was referring to, as in a heavier rifle. Not double weight, but more stable. I felt like some of those groups were not the best representation of my max capability.

It’s one reason I’ve dropped down to a 6 PRC as my main hunting rifle. I despise recoil. Call me a wimp or whatever, but I like 22 cal centerfire and 6mm.

 

[Schmo]

I know I’m not an expert marksman, but I am going to try out a KRG Bravo for hunting, and see if the weight bothers me. I would rather cut weight from my scope and suppressor, than to run an ultralight stock. I’m not opposed to a 9-9.5 lb hunting rifle. It’s all about capability. I would rather the weight be in the stock, acting as a ballast, than have a heavy scope and such.

 

[stan_wa]

I'm still waiting for ONE SINGLE REFERENCE to a test of small seating depth or powder charge tweaks done with >10rds per sample that demonstrates a statistically meaningful difference.

but we have several examples that shows, NO significant difference. I think a little big of pshycology helps us understand this. We have a very hard time accepting that our efforts produce no change. Its turly hard to for use to accept that putting in the extra effort of all these load methods is meaningless thus we want to belive we can fix our load with small tweeks.

Right -- validating small differences requires large sample sizes.

that not quite my point. im really trying to say that 25% change in group size, is not usually statistically significantly different. But we think it is. I say this cause i have run T test on many several load sets of different loads radii and confirmed they were not different. one may would look at a 25% change in group size and assume it was significant. Large sample sizes are only need to detect small differences. If the difference are large even small samples will be identifiable as different. let me give some examples.

Id 13 is not different statistically from load 12b even tho the group size is .96 vs.75. these groups have different powder charges.



but 12 above is obviously different and statistically different. than load 2. This is what happen when i changed powder type



before i knew small changes in powder and seating didnt matter i tested seating depth and powder charge here is some data as you can see the group size and MR are not different . hell im even stubron enought to still test cause it , even tho it never seems to matter

 

[Flyjunky]

What do you mean by this? That this site has somehow determined the numbers in the podcast were wrong?

So, you are making a blanket statement that tuning doesn’t work at all and it can’t be done? Doesn’t matter the rifle or load? I have a hard time with blanket statements.

Edit: what are you now considering small tweaks?

 

[Jordan Smith]

I am telling you that no, I have never seen a test with 10+rd groups show any evidence of nodes or tuning being effective. I've seen about 10 million with 3-5rd groups claim to find nodes, and I've seen 0 of those tests repeated and discovered the same nodes. Please link just one!

Well, the goal posts are moving with 10+-round groups now being a stipulation, but I have done that myself several times. Why did you choose 10-round groups in this quote? Of course 10-round groups are better than 3- or 5-round groups, but my point is that 10 still isn't even close to enough if we're after statistical power, whether they show a difference between charge weight and seating depth tweaks, or not.

 

[Jordan Smith]

Modern Advancements Vol 3, Part 1. The tests he ran were on barrel tuners, but the outcomes were the same. And yes, if you believe small changes in powder or seating depth make a difference, than you ought to believe barrel tuners work too. And yes many HOF BR shooters swear by barrel tuners. And NO they aren't shown to do anything!

Okay, so not powder charge and seating depth changes. Tuners are not the same.

 

[Jordan Smith]

Goal posts have not moved. What they found is significant changes such as changing bullet or powder had the greatest measurable impacts on precision.

They have moved a couple of times. It's a very different assertion to say that seating depth and charge weight makes no difference, compared to saying that small tweaks are not resolvable and only large changes make a statistically meaningful difference.

 

[Jordan Smith]

10 shot groups at bare minimum but 30 is more appropriate for validation.

Frankly, 30-shot groups are a bare minimum if we're after statistical meaning.

 

[Flyjunky]

They have moved a couple of times. It's a very different assertion to say that seating depth and charge weight makes no difference, compared to saying that small tweaks are not resolvable and only large changes make a statistically meaningful difference.

Exactly

 

[stan_wa]

Frankly, 30-shot groups are a bare minimum if we're after statistical meaning.

That true if the samples are similar . If they are very different, even smaller samples sizes can still be high confidence

More shots is better instead of arguing about what sample size is needed it’s best to just run a t test this takes into consideration the sample size.

 

[mxgsfmdpx]

Zero check before hunting. Maven RS1.2 had dialed itself up 0.1 MIL. My fault for not checking (user error). Shot the magazine out anyway.

Factory 8 twist Tikka 223 chopped to 16” with factory black hills 77 TMK ammo 5 shots.

What should I TwEaK?!?!? Or should I sell it for a “comp gun”

 

[Jordan Smith]

How did you determine this? I am truly interested in seeing if seating depth makes a difference. I have seen small groups change n size with changes. But I have yet to see anything that shows a real difference. Please keep in mInd that even a 20 shot group size of .75” vs 1” or 1.5” vs 2.0” is not a real difference. What I do mean by real difference? I mean using a t test on individual radii. I know it’s a pain to do.

If large changes in seating depth
.05” or powder 2 grain don’t make a change, seems easy to say a small change won’t matter.

True, but that's a big "if."

 

[Flyjunky]

Caveat - they do say in some cases a lower powder charge can produce measurably less dispersion, if it's worth the sacrifice in velocity. Which I'm sure some would identify as a "node", but the ballisticians do acknowledge it.

Isn’t that considered tuning a load?

 

[huntnful]

Zero check before hunting. Maven RS1.2 had dialed itself up 0.1 MIL. My fault for not checking (user error). Shot the magazine out anyway.

Factory 8 twist Tikka 223 chopped to 16” with factory black hills 77 TMK ammo 5 shots.

What should I TwEaK?!?!? Or should I sell it for a “comp gun”

View attachment 955118

.2 gr. powder difference would get rid of that vertical “stinging” for sure. Worth spending at least 500 rounds of testing on.

 

[Schmo]

Zero check before hunting. Maven RS1.2 had dialed itself up 0.1 MIL. My fault for not checking (user error). Shot the magazine out anyway.

Factory 8 twist Tikka 223 chopped to 16” with factory black hills 77 TMK ammo 5 shots.

What should I TwEaK?!?!? Or should I sell it for a “comp gun”

View attachment 955118

Probably back off .3 in powder charge, and seat farther out by .020”, and then do a 100 shot composite and you should be golden.

Oh yeah, switch to a 210M primer. That alone will shrink the group by half