What's the definition of a "Group" ? (of shots)

[FEENIX]

I hate complicating things unnecessarily.

Q: What's the definition of a "Group" ? (of shots)

A: A cluster of shots from the load developed for a given purpose, such as hunting, target, competition (timed), etc., to meet the intended goal/parameters.

 

[FEENIX]

I was pondering, at which point, or interval, does a 3-shot group become three individual shots ?
Do you get up to sip coffee or pee, move the rifle, then re-focus ?
Do you discard the first cold bore shot, and only count warm barrel shots ?

I understand different folks have their own ways of doing things. I'm wondering what would
be a better method, what would give statistically better info (in theory anyway).

I'm probably just splitting hairs.

"If" you are hunting, this is your most important shot - cold bore.

 

[hemiford]

"If" you are hunting, this is your most important shot - cold bore.

Right, but just for purposes of statistics and measuring group size, wouldn't you want all parameters to be as close as possible,
including barrel temp ?

How useful would it be to take one cold bore shot every day for ten days in a row ? (Of course you can't control the weather !)

Edit: Maybe I should have made the thread title : "How useful is Group info ?"

Edit again : That would give you a different and possibly useful group statistic, 10 1-day shots that is.

 

[FEENIX]

Right, but just for purposes of statistics and measuring group size, wouldn't you want all parameters to be as close as possible,
including barrel temp ?

How useful would it be to take one cold bore shot every day for ten days in a row ? (Of course you can't control the weather !)

Edit: Maybe I should have made the thread title : "How useful is Group info ?"

It is beneficial for me. However, if you are going for a statistical inference/reliability, you would need a larger sample. So, 10 is not enough, but it is better than nothing. As long as you establish some assumptions and limitations of your test, you should be OK. You get to determine what is acceptable for your intended purpose.

Yes, you cannot control Mother Nature. This is one of the reasons I do load development around the September time frame and finalize my load around the first week of October for my fall hunt here in MT.

 

[Hand Skills]

Right, but just for purposes of statistics and measuring group size ....

From a statistical point of view, 3 shots doesn't hold a lot of value.

5 shots tells a little more,

...but 10+ shots is where statistics start to have some value.

For example,

I like to shoot the first shot of the day into a 'first shot' target. After 10 days, I have 10 shots - this is a pretty accurate reflection of my abilities with a given rifle... and it keeps me humble.

 

[Roughrice]

3 shots in 90 seconds ?
3 shots in 3 minutes ?
3 shots in 30 minutes ?

5 shots in 50 seconds?
5 shots in 75 minutes ?
5 shots in 5 hours ?

How quick do the follow-up shots have to be after the first cold bore shot ? To be considered in that same group.
The barrel is going to be warming up, so all the shots were not shot under identical conditions.

Depend on what I'm grouping for.

1) Hunting rifles. — 3 shots in 1-1.5 minutes…That's because follow up will be quick.
2) Bench rifles for timed relays —-10 shots with about same 1-1.5 minute intervals.
3) For best grouping possible out any rifle. —- 5 shots with at least 2+ (minutes between shots (depending on outside and barrel temp)

 

[Jim’s Hunt]

I always send a warmer round down the barrel before testing group rounds. I wait 2 minutes between shoots and use a chamber chiller for those 2 minutes.

On the other hand I thought the true definition of a group was 5 guys sitting around a hunting camp fire telling hunting lies and having a beer or 2

 

[sturner]

Right, but just for purposes of statistics and measuring group size, wouldn't you want all parameters to be as close as possible,
including barrel temp ?

How useful would it be to take one cold bore shot every day for ten days in a row ? (Of course you can't control the weather !)

Edit: Maybe I should have made the thread title : "How useful is Group info ?"

Edit again : That would give you a different and possibly useful group statistic, 10 1-day shots that is.

All shoots count to the group if you can't put 5 in the same hole keep working on the load and the shots have to be taken in succession my time is one right after the other not as fast as I can but pretty close together BUT this is my way

 

[dfanonymous]

From a statistical point of view, 3 shots doesn't hold a lot of value.

5 shots tells a little more,

...but 10+ shots is where statistics start to have some value.

For example,

I like to shoot the first shot of the day into a 'first shot' target. After 10 days, I have 10 shots - this is a pretty accurate reflection of my abilities with a given rifle... and it keeps me humble.

I think that's why PRS typically likes the 10 shots in 2 minutes. Again, usually most of us are using heavy short action guns with large barrel profiles and not a care in the world about barrel life.

Which I think helps qualify that "it depends" which displine we are talking about.
I just don't want to open the PRS can of worms on here.

 

[Dirtrax]

I started chuckling to myself when I realized darn near every rifle on these forums are "1/2 moa when I do my part."
In all seriousness the folks who out right say or allude to application are on point imo.
The logical answer is to log your results from groups shot quickly and slowly. Is there a difference? Apply the results to YOUR application. It always boils down to shooting with a goal in mind. What you don't know you test and learn. Questions are fine but honestly we're all speculating here. Go Learn and report.

 

[waspocrew]

I used to take about 1 min between shots - now, not anymore. Wastes a ton of time at the range. If it's really hot and I'm worrying about the barrels cooling, I have a cooler with ice water and cold rags to help.

At this point though, I tend to shoot 4-5 shots with maybe 15 seconds between for my "groups".

 

[Rflshootr]

It depends on what I am doing. If it is load development, it is 3 shot groups...because if it won't shoot 3, it won't shoot 5. If it is practice after load development, to show consistency, it's 5 shot groups. Whichever it is, I shoot conditions. If a condition is holding, I keep shooting the group. If conditions change, I pause until the condition returns and then finish the group. I always shoot with wind flags. Then let the barrel cool between groups.

 

[jerbur]

Asking about group size is like asking about fast cars, good looking ladies and big fish .
All are relative to the person asking or talking.
Depends on YOU and what you're looking for.

 

[Rflshootr]

I usually do 2 minutes between each shot. Either 3 or 5 round groups. All depends what I am doing.

To truly see how your rifle is shooting, shot one round every day, same time each day, at the same target, for 3-5 days. This will provide you a cold bore group and how the rifle is going to preform, cold bore accuracy.

So, if you shoot the 1st day at 80° and zero wind, and the next day a cold front comes through, and it is 65° with a 10-mph cross wind and the 3rd day it's 90° with high humidity and heavy mirage, does that really tell you cold bore accuracy?