Are three shot groups valuable?

[ButterBean]

No it is not.
Maybe some day you'll test the difference and see this.

I get into a local/annual accuracy contest here. It's simple, get in line, when you're up drop your rifle on sand bags provided on a table. Shoot one shot into a 1" dot at 200yds. Hit it & you go to the back of round 2 line. Miss and you're done.
By round 5 the dot goes to 3/4", at round 10 or last 2 shooters, it's closest to center of mark. With 50 shooters and nearly half eliminated, it takes an hour from round 1 to 2, 1/2hr from round 2 to 3, 15mins to 5mins with shooters left in remaining rounds. Before the 10 round [let's end it] rule, I've seen it take 14 rounds for a winner. And there is a pig picken/beer & a lot of fun with this.

Started off with hunting guns, just before deer season here. Now it's full blown 6PPCs, 30BRs, 6Dashers from out of county/state mixed in.
The benchrest/non-hunting guns do ok with this, maybe ~1/2 of them that is.
The killer for them, as it is for everyone else, is the transient temperatures of their metal. These changing shot rates, with no sighters/foulers/good feelers between record shots.
VERY precise guns after 6-7 sighters and with a ~1min shot rate, fall to pieces with a single shot 10mins, or 20mins later.

So it's been close to half & half hunting gun to BR gun victories the past 10yrs.
Keep in mind that hunting guns are no where near BR guns for precision (group) shooting.
Doesn't matter.
What wins is a shooter's understanding of this, and their preparations for the contest.

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[Calvin45]

^^^^^^^^^^^^^^^^^THIS^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Yeah whether it's snipers or long range hunters that's the difference between real world field performance and competition…the first shot is really the only one that matters.

Especially for hunting, this is why I don't care that much about barrel life…you recall I was so excited to have hit 4000 fps…right away you get people saying "yeah but what about barrel life?"

Who cares! The performance of that all important first shot kicks a**! That's what I care about.

 

[asd9055]

I was going to stay out of this, but, why not...
I am not a competitive shooter, nor do I have any custom rifles for competitions..
I only have hunting rifles. I had to shoot a follow up shot twice, once Hunting Elk in Colorado and once hunting Wildebeest in S.A.
My policy is this. I sight in at 300 yards. (this is after a settled on bullet and load). Will do 3 successive shots. (From sticks, or what ever method I forsee hunting on that trip) If they are in the "vital" target I call it good. (unless I am harvesting a deer in Texas, just one shot to check th rifle)
This has always worked for me.

 

[Mikecr]

What test do you suggest I do that could demonstrate an precise rifle isn't capable of better accuracy than a imprecise rifle?

Pick a bad range for you, and a bad shot rate for your gun, and shoot single shots on a target. Keep an objective measure from center of target to center of each impact, totally ignoring any grouping about it. Then accept or reject the worst of your accuracy capability.
Of course you'll need to validate accuracy at your furthest intended hunting range (pick a limit range).

Do this over different days & conditions. If/as you obsess on this like I have, you'll end up tweaking the cold bore load, ammo handling, bore cleanings, field rests, and you'll get pretty serious about scope testing. With purely hunting guns, you won't care about grouping anymore. You'll see precision as disconnected to accuracy.

Especially for hunting, this is why I don't care that much about barrel life…you recall I was so excited to have hit 4000 fps…right away you get people saying "yeah but what about barrel life?"

People who take their guns to a range like to have fun. They like group shooting.
A lot of them are having fun with guns they rarely hunt with.
If you're group shooting a gun, then accurate barrel life matters -a lot. Replacing barrels sux...

 

[biednick]

Keep an objective measure from center of target to center of each impact, totally ignoring any grouping about it.

If I do this with 2 guns with differing levels of precision the more precise rifle will place its shots closer to the center of the target assuming the scopes on both rifles are adjusted to the same POI. If the scopes are perfectly adjusted to hit POA this test is just a measure of group size. I can do this test over a couple minutes, a couple hours, a couple days, a couple months, or a couple years. I can do it at any single range or a variety of ranges. I can do it all from a bench or from realistic field positions. Regardless, I will be testing both precision and accuracy, and the rifle with better precision will display better accuracy if all else is equal. I may not measure precision directly but it will affect my results. I'd just be testing under a different set of parameters than a competition shooter would choose.

Let's say I do your test and don't accept the worst shots I take. My options are to move my group closer to center or make my group smaller (more precise). If my group is already centered the only option I have is to reduce my group size.

The attached picture shows what 2 groups, both 1.5" off center, would look like. The green circle is 3" in diameter showing both white circles are the same distance from the centeral dot. The white circles show the area a 1" and 2" group would land in. The red circles show the area bounded by the centeral dot and the shot group (in other words, the red circles are what you suggest measuring in your test). Which is more accurate? Which is more precise? If you saw these results over the course of your testing, which would you choose to hunt with?

 

[DocB]

So the next day I fired two more and got the group below. For the next week I banged steel with it at my CO place. But as I was doing so, I noticed my velocities were going up (bbl had less than 30 shots when I fired the group below). So this morning I took the same target to my 100 yard range, and fired two more. Seven shots in .483".

I do get a laugh when guys say "I never shoot 3 times at an animal, so why test loads using 5 shot groups?" Well, as you can see, while my seven shot group is great, it got bigger the more shots I fired.

Shooter fatigue.

 

[Mikecr]

If I do this with 2 guns with differing levels of precision the more precise rifle will place its shots closer to the center of the target assuming the scopes on both rifles are adjusted to the same POI.

Your picture shows group centering about edges of the green circle, NOT about the center.
If the green circle is killzone for range, then ANY shot hitting outside of it is a failure that just reduced your accurate range capability.


This is great precision, but horrible accuracy:

If the 10-ring represents my killzone, then this shooting equals no more than 5 missed groundhogs to me.
I am familiar with this situation, having developed a Tubb2000, 6XC, for 600yd shooting. I could shoot sighters to stable barrel temps, move over to this same target, and shoot a competitive group (not quite as tight as pictured though). However, if I were to then wait 30mins, hop back behind the gun and shoot another group (with no sighters/warmers), that group would be far larger. Too large.
What would happen is that shots would walk back into settle, with the last shots touching.
Thing is, I'm not a competitor, and that gun was not accurate enough for my use, so I just sold off the whole system (to a competitor).
This is why I suggest avoiding tube guns for hunting guns (no matter how good).

This is precision PLUS accuracy:

If this shooting was 10min apart or more between shots, then this qualifies for groundhog accuracy at 600yds.

 

[bamban]

Your picture shows group centering about edges of the green circle, NOT about the center.
If the green circle is killzone for range, then ANY shot hitting outside of it is a failure that just reduced your accurate range capability.
View attachment 379605

This is great precision, but horrible accuracy:
View attachment 379590
If the 10-ring represents my killzone, then this shooting equals no more than 5 missed groundhogs to me.
I am familiar with this situation, having developed a Tubb2000, 6XC, for 600yd shooting. I could shoot sighters to stable barrel temps, move over to this same target, and shoot a competitive group (not quite as tight as pictured though). However, if I were to then wait 30mins, hop back behind the gun and shoot another group (with no sighters/warmers), that group would be far larger. Too large.
What would happen is that shots would walk back into settle, with the last shots touching.
Thing is, I'm not a competitor, and that gun was not accurate enough for my use, so I just sold off the whole system (to a competitor).
This is why I suggest avoiding tube guns for hunting guns (no matter how good).

This is precision PLUS accuracy:
View attachment 379600
If this shooting was 10min apart or more between shots, then this qualifies for groundhog accuracy at 600yds.

Thank you.

Bugs me when people use the words interchangeably.

The Difference Between Precision and Accuracy

People tend to confuse precision and accuracy, and many of the definitions out there aren't entirely clear. Here's the easiest way to see the difference.

danielmiessler.com

 

[asd9055]

Your picture shows group centering about edges of the green circle, NOT about the center.
If the green circle is killzone for range, then ANY shot hitting outside of it is a failure that just reduced your accurate range capability.
View attachment 379605

This is great precision, but horrible accuracy:
View attachment 379590
If the 10-ring represents my killzone, then this shooting equals no more than 5 missed groundhogs to me.
I am familiar with this situation, having developed a Tubb2000, 6XC, for 600yd shooting. I could shoot sighters to stable barrel temps, move over to this same target, and shoot a competitive group (not quite as tight as pictured though). However, if I were to then wait 30mins, hop back behind the gun and shoot another group (with no sighters/warmers), that group would be far larger. Too large.
What would happen is that shots would walk back into settle, with the last shots touching.
Thing is, I'm not a competitor, and that gun was not accurate enough for my use, so I just sold off the whole system (to a competitor).
This is why I suggest avoiding tube guns for hunting guns (no matter how good).

This is precision PLUS accuracy:
View attachment 379600
If this shooting was 10min apart or more between shots, then this qualifies for groundhog accuracy at 600yds.

Great explanation. Thank you

 

[Mikecr]

Bugs me when people use the words interchangeably.

There is another perspective still, which I cannot surmise practical use of.
Basically, it's combined averaging of X & Y from mark.
But this is NOT 1/4moa accurate,, it's not even 1/2moa accurate:

 

[bigngreen]

Three shot groups matter, without them there is no reason to shoot more!

 

[biednick]

Your picture shows group centering about edges of the green circle, NOT about the center.
View attachment 379605

Yes, that's correct. That's exactly what I stated in the post I attached the picture to. The green circle is just a circle of arbitrary size to show the two white circles are centered equidistant from the central dot. The red circles represent the measurement from the central dot to the farthest shot in each group, which is the largest value of the measurement you mentioned. Either, both, or neither of these groups could provide adequate accuracy for a particular scenario.

This is great precision, but horrible accuracy:
View attachment 379590

Again, that's correct. A quick scope adjustment would make this precise group a very accurate group as well.

This is precision PLUS accuracy:
View attachment 379600

Would this group be as accurate if the group size was doubled? In other words, would this group be as accurate if the rifle were less precise? To be clear, I am not asking if it will still provide adequate accuracy for groundhog hunting at 600 yards. I am asking how the accuracy, when measured from POA to the center of the bullet hole as you mentioned in a previous post, will change as precision is reduced.

 

[Mikecr]

On the group out at the 8-ring, the shooter had a 3min sighter period before this record shooting. Do you think he just wanted a lower score?
For the accurate group, he did not catch the X-ring, so regardless of precision there is potential to shoot more accurately.

In reality, neither groups pictured demonstrate potential for hunting.
They were shot after a sighter period, from a concrete bench and bench rest, at a forever fixed range, with wind flags, martinis shaken/not stirred, from guns that are not field practical. I was just throwing up obvious differences between pure precision and accuracy.

If you think this is no more than scope adjustments than try it.
Pull a gun from it's case, drop it on a field rest, adjust the scope, hit your mark with one shot. How accurate are you at that distance?
If good, that is good. It's what this is all about.

 

[biednick]

On the group out at the 8-ring, the shooter had a 3min sighter period before this record shooting. Do you think he just wanted a lower score?
For the accurate group, he did not catch the X-ring, so regardless of precision there is potential to shoot more accurately.

In reality, neither groups pictured demonstrate potential for hunting.
They were shot after a sighter period, from a concrete bench and bench rest, at a forever fixed range, with wind flags, martinis shaken/not stirred, from guns that are not field practical. I was just throwing up obvious differences between pure precision and accuracy.

If you think this is no more than scope adjustments than try it.
Pull a gun from it's case, drop it on a field rest, adjust the scope, hit your mark with one shot. How accurate are you at that distance?

You did not answer the question I posed. How would the accuracy of the group in the 10 ring be affected if precision is reduced and no other changes are made?