Show your Tikka ten round groups

[16Bore]

You fellas crack me up

Center your crosshairs on the 10 round group. Now go shoot and have fun.

 

[RCB]

I got distracted at the desk and started thinking along the same lines... tough thing is with groups is it's the max value, not the mean that defines the group... I was thinking one could take group measurements with each consecutive shot to see where the line flattens out. Will be pretty variable among rifles which is maybe why folks just stick with an easy number (like 10).

Right. The basic idea is that if you only shot a single 10-shot group, then the best estimate for your 95%-confidence target size is about 1.3 times the size of that group. That estimate would still be pretty noisy.
There are other ways to estimate. You could fire a single 20 shot group, find the deviation of your 2nd-worse shot, and that would estimate the 95% range.
Of course all of this assumes a perfect 0, which might be a pretty strong assumption.

IMO, the best way is to eschew all these stats and do it the old-fashioned way.
Step 1: Zero your rifle, by whatever method you prefer. Be precise.
Step 2: Shoot your rifle 10 or so times from some distance, aiming at a particular point. Do not change your zero during this time.
Step 3: How far is your worst shot from the point at which you were aiming? Multiply that distance by 2; that is about the target size you can shoot at that distance. If your worst shot was 1.5" from the target point, then you can shoot a 3" target pretty comfortably.
Note that this is not a measure of group size. Your group size will almost certainly be smaller than this number. But hunting is about hitting a target, not small group sizes.

 

[Ens Entium]

Yeah, I've spent my fair share of time studying probabilities in college, analyzing data sets and employing statistical methodology in a professional capacity, as well as shooting a decent amount recreationally. I'll go out on a limb and say that like you, I like shooting as well as taking a deeper dive into the math/science behind it. However, you don't need to have a comprehensive understanding of statistical principles to recognize that more data is better than less and that smaller data sets (in terms of round count) are not indicative of the mechanical accuracy of the rifle, ammo, scope, and/or shooter when compared to larger data sets.

For me, I haven't shot a 3-shot group in well over a decade. I typically shoot 5-shot groups, but occasionally will shoot 10- or 15- or 20-shot(ish) groups. I keep records of data, don't call 'fliers', don't wait for the rifle to cool between shots, and aggregate the data over distance and conditions to obtain a broader understanding of my abilities using my equipment. Plenty of guys go into more detail than I do, and plenty don't.

Not to sound rude, but I don't necessarily care what other people do. HOWEVER, when I read someone post 'there's math to support 'X'-process.....the best ballistics testing facility on the entire planet performed a comprehensive study......etc. etc.' I think "that's awesome, I like facts and data, let's see it!" Maybe there's something I could be doing better or maybe there's not - either way I might learn something or just have a good read.

Call me crazy, but I don't take it as gospel when a nameless faceless guy/gal on the internet says "trust me, I'm a secret internet expert". Instead, I prefer to see the data that is actually being referenced so I can make my own decision. Otherwise.....

Statistically there is a way to quantify outliers (Pearson and Hartley or Grub's Test) to objectively say whether or not they should be included.

That being said, there is no reason to delve that deep when it comes to something so influenced by human error.

 

[16Bore]

Yep, that’s a big reason why I don’t waste the time. It’s not barrel harmonics or SD or anything else - I’m the problem.

Yep. Then you gotta sort out the “mistakes” you made. Then the “mistakes” that you constantly repeat that don’t look like “mistakes” because the bullet holes aren’t telling you otherwise.

Then somedays, ya just can’t shoot.

 

[HighUintas]

Yep. Then you gotta sort out the “mistakes” you made. Then the “mistakes” that you constantly repeat that don’t look like “mistakes” because the bullet holes aren’t telling you otherwise.

Then somedays, ya just can’t shoot.

I've got a question on my mistakes. This is something I've thought of often and just haven't asked anyone to be sure of it.

For parallax, I was always under the impression that if I have my eye positioned so that the shadow around the edges disappear, then my eye should be on plane with the reticle and won't have parallax error. That is how I check to make sure I'm on plane. I've read that some people will leave their head back from the scope just enough to give them a thin ring of shadow around the edge that they will use as a reference to center their eye on plane. I know you can also move your head around and look for the reticle to float, but I have a tough time doing that when behind the scope .

If I have my eye close enough, it will remove the shadow but I can still move my head slightly side to side without any shadow showing up. So this makes me wonder if some of my inconsistency is coming from parallax error even though I've been thinking I'm checking for it and eliminating it.

In one of my target pictures their is a clear pattern of the shots going high left to low right. If I'm using a scope at 10x power at 100 yds with the parallax from xed for 150yds, could a slight parallax error that isn't obvious to me with the way I've been checking for it cause that big of group dispersion?

 

[16Bore]

Bud, I couldn’t tell you. I know I’m looking at the X. You can look at the crosshairs and move your head and see them dance around the target. No idea what’s going on around the edge, just the middle.

 

[Formidilosus]

Post up the white paper so we can see the standards, methodology, analyses, correlations, exceptions, conclusions, etc.

Are you really this obtuse, or is it just an internet persona?

Call me crazy, but I don't take it as gospel when a nameless faceless guy/gal on the internet says "trust me, I'm a secret internet expert".

Feel free to find one post with me claiming to be an expert, or suggesting anything other than to shoot more. Though it is telling that you avoid refuting or discussing the subject, and instead resort to drive by remarks.

What I wrote in here is easily seen by anyone that goes out and tries it. Menhaden-man showed in his simple spreadsheet that at 10 rounds, a 2 MOA gun is inside of a single click on most scopes for zeroing.

 

[Formidilosus]

I’ve thought of taking a crack at this one day for the hell of it... taking a pic of the target every shot through my spotting scope and then seeing how the group size grows with shots fired.

One of the ten round group pics I posted earlier was three- 3 shot groups, and a single to make ten.

1st three-



2nd three-




3rd three-




All ten-



Compare the 3x3 round groups with the other groups shown for the rifle I posted earlier. No a whole lot of difference, but the MPI shifted quite a bit between each group, enough to cause issues at medium to long range of you “zeroed” of of any of them and the 10th round changed the MPI of the group again.

 

[Formidilosus]

If the main purpose of shooting a group is to center the cone over point of aim, and we are shooting past close ranges, than we want to eliminate errors that will lead to misses. In zeroing, being inside of 1 click/increment of the scope helps that. .2mil/.5moa can start to lower hit rates on big game size vitals at medium ranges, but a .1mil/.25moa error doesn’t really show up by itself.


The above target with marks for center of each three round “group” marked. Green is group 1, yellow is group 2, blue is group 3, but red is the actual center.




This is actually less shift from each three shot group inside the cone than what is usually seen. Even still there is approx. .2 mil difference between the 1st group and the actual center, a .1 mil between the 3rd group and center.



There is a point of deminishing returns. 3 or 5 shots is not enough for the vast majority of rifles to get a high confidence zero. 30 is more than required for most. The sweet spot is 8-20’ish shots- Anywhere in there is pretty good. 10 just offers a pretty reliable way to be zeroed within one click on the scope, is easy and simple to do, and is half a box of ammo. I personally confirm with a 30 round group for most of my rifles, as most of them are not 2 MOA guns, and I require a extremely high confidence of having POI match POA.


The end result- shoot a bunch of bullets, find the center of all of them (do not use any group reduction nonsense), adjust the center to POA, shoot a bunch more to confirm zero.

 

[fbhandler]

If the main purpose of shooting a group is to center the cone over point of aim, and we are shooting past close ranges, than we want to eliminate errors that will lead to misses. In zeroing, being inside of 1 click/increment of the scope helps that. .2mil/.5moa can start to lower hit rates on big game size vitals at medium ranges, but a .1mil/.25moa error doesn’t really show up by itself.


The above target with marks for center of each three round “group” marked. Green is group 1, yellow is group 2, blue is group 3, but red is the actual center.

View attachment 185355


This is actually less shift from each three shot group inside the cone than what is usually seen. Even still there is approx. .2 mil difference between the 1st group and the actual center, a .1 mil between the 3rd group and center.



There is a point of deminishing returns. 3 or 5 shots is not enough for the vast majority of rifles to get a high confidence zero. 30 is more than required for most. The sweet spot is 8-20’ish shots- Anywhere in there is pretty good. 10 just offers a pretty reliable way to be zeroed within one click on the scope, is easy and simple to do, and is half a box of ammo. I personally confirm with a 30 round group for most of my rifles, as most of them are not 2 MOA guns, and I require a extremely high confidence of having POI match POA.


The end result- shoot a bunch of bullets, find the center of all of them (do not use any group reduction nonsense), adjust the center to POA, shoot a bunch more to confirm zero.

I like/agree with what is being said here. A question I have then, is should that “cone” be shot in such away as to eliminate as much shooter error/inconstancy as possible (ie leadsled etc.) giving us a better picture of rifle/ammo relationship or do we want that cone to include our inconsistency’s?

 

[HighUintas]

Somebody else needs to post up some pictures to get this train wreck back on the rails!

Agreed! I'm going to range today. I'll post my birdshot pics

 

[HighUintas]

Here's today's groups. Not bad, but it looks like there's a slight POI shift from group 1 to 2. I'm not sure what caused it but I think maybe cheek pressure or shoulder pressure.

Here's what I worked on today.
1. Getting square behind the gun for consistent shoulder/recoil pad placement and consistent recoil.
2. Trigger control and trying to 'see' the impact. I used my 17hmr while letting the '06 cool to practice both of these. The trigger is heinously heavy and creeky. It's good practice.
3. Ignoring the voice that says "don't screw up" as I'm about to break the trigger on the 2nd group shots.
4. Not think about the statistics of it

Also, I'm about 150 rounds since the last full copper/carbon cleaning and 53 rounds since I last put a patch in the bore I did clean the chamber and neck area yesterday though. Total round count is 372

 

[16Bore]

50 year old rifle, 30 year old scope, factory ammo, gave it away last weekend.

There’s statistical significance to a 3 and two 2’s.

 

[HighUintas]

50 year old rifle, 30 year old scope, factory ammo, gave it away last weekend.

There’s statistical significance to a 3 and two 2’s.

View attachment 185612

What Tikka model was that? That had to have been worth a pretty penny

 

[16Bore]

Wintikka

 

[DJL2]

Lots of discussion...here's some non-random noise from me...worth what you paid...

I remember reading, years ago, an essay written by someone reflecting on a practice he used (with attribution to White Feather). He went out every day, no matter the conditions, a fired a cold bore shot at 200 yards. It took time, but he eventually amassed a fair amount of DOPE and could use it to surmise a few things about his own ability, as well as the rifle/ammo/shooter system.

That's not an easy thing to do, but it alway struck me as interesting. We shoot groups for confidence - it might be confidence in ourselves, the rifle, the ammo, the optic, all or some of those things in combination. There's something to be said for devising a means of measuring the shooter's ability to produce performance on demand. The way we shoot groups or strings doesn't necessarily do that.

There's definitely some goodness in aggregating your data. Group size is a stand in for what we actually want - the deviation of individual shots from desired POI and the probability distribution deduced for that rifle/ammo/optic. Group size is useful in the sense that it eliminates zero error and/or aiming error as long as the error is consistent, and it's convenient.

Conditions and variables change all the time. That's true within a shot string or for groups shot over days. That complicates a test of "pure" accuracy, but is that really what we're after? We're testing the shooter guided system, no? I'd argue we're testing our ability to control for variables as a shooter at least as much as the rifle's ability (particularly if the latter can be established with confidence and thus becomes well defined).

I've got my first Tikka in hand now...when I manage to get it scoped and fed, I'll be curious to see how we get on.

 

[16Bore]

The pursuit of perfection destroys the good.

 

[mxgsfmdpx]

Less blabbing. More groups.

 

[16Bore]

Let me ask, in all seriousness, what do the groups actually prove for you?

 

[Deplorable77]

Some days you're Carlos Hathcock , the rest of them your just the same as every other schmuck with a rifle