Why I don't like 3 shot groups

[forrest r]

I use 3 shot groups when sighting something in. Simple enough shoot 3 shots, find the center of those shots, measure to what you're actually aiming at/trying to hit and move the sights/crosshairs/dot/ect accordingly.

When using 3 shot groups as an indication of the accuracy of a load, it's extremely misleading.

Was out yesterday shooting cast in the 308w. Shot 4 different 10-shot groups and they were 2 1/2", 2 1/4", 2 1/4" & 2 1/8". 40 shots +/- 2 1/4" To me this is real world results and testing I can work with.

I always bring something with me to plink with between sets with the 308w letting the bbl cool. So I put a burris fastfire III on a 10" bbl'd contender that had a 3 MOA dot. Sighted it in @ 25yds with 1 of it's favorite plinking loads, Mihec's 432-640 cast with hp pins weighing +/- 265gr and 7.0gr of bullseye powder.

So I got the contender on paper and setup some targets @ the 100yd line. I use NRA 50yd smallbore targets, 3 in the top row & 2 in the bottom row. I want to get the contender dialed in so I could bang on some steel between sets with the 308w. Love the sound of steel rings!!!

Anyway the target is cluttered with bullet holes, same target stand I used the other day burning up a bunch of lee 310gr bullet. The 432-640's are the holes in the NRA targets.


I used the top 3 targets to dial the fastfire III in. Man that thing is touchy, 1 click goes a llloooooonnnnngggg way with the bullet!!!! When I felt I was close I used the bottom 2 targets for the final zero along with finalizing which brightness of the dot I wanted to use. The bright dot was fuzzy on those targets, hard to center the dot. Shot both rows of targets left to right.

The bottom left target is 3 1/2" outside to outside
The bottom right target is 1 1/2" outside to outside

I know it's only 2 targets but:
IMHO, I was shooting 3 1/2" groups with that contender. Any firearm is only as good as it's worst shot/group.
I could say I can do 1 /12" groups @ 100yds "If I do my part".
Averaging a bunch of 3 shot groups is always misleading simply because there will always be those smaller then normal groups added into the mix that doesn't reflect what is really going on.


Anyway just another opinion, not singling anyone out or anything like that. Nor is my way of doing things the only way. Myself I like a bunch of holes to sort things out. More often then not it's not so good. But this gives me something to work at/achieve. Along with getting better at identifying what is going on and how to correct issues.

 

[Charlie98]

You are echoing what many of us have been saying for a long time. I would say 10- or even 20-shot groups give a better picture of a firearm's capability, but also the shooter's general ability to shoot that firearm, to include whatever posture (seated, prone, rested, etc) is used.

 

[mcb]

I like 5-shot groups, preferably three to five 5-shot groups to average to give me a good feel for the accuracy potential of a given setup.

 

[AJC1]

Depending on purpose I would agree. For target shooters a 10 shot group is a strong indication of the systems accuracy including you. For a guy that's hunting really only the cold bore shot matters

 

[earlthegoat2]

For me and the hunting accuracy that is the only thing I care about, 3 shot groups are fine and anything more just heats up the barrel which is usually unrealistic in a hunting situation but even if it happens it will be negligible to what you are trying to accomplish.

When I post groups that I am proud of on here it will be a 5 shot group though just to shut up the folks who will invariably say that a 3 shot groups is not good enough.

It seems 5 isn’t either now.

 

[AJC1]

For me and the hunting accuracy that is the only thing I care about, 3 shot groups are fine and anything more just heats up the barrel which is usually unrealistic in a hunting situation but even if it happens it will be negligible to what you are trying to accomplish.

When I post groups that I am proud of on here it will be a 5 shot group though just to shut up the folks who will invariably say that a 3 shot groups is not good enough.

It seems 5 isn’t either now.

You just say what your discipline is for clarity. As mentioned earlier what your trying to accomplish changes what people think. If you don't provide critical information, commonly an inappropriate assumption is made.

 

[forrest r]

Odd, when I setup a rifle for hunting I typically shoot a shot and find something else to do. Then come back 15/20 minutes later and shot another shot getting an idea of what's going on.

I also like to re-test in the weather conditions I'm going to be hunting in. Namely testing in 85* weather and then hunting in 20*'s never worked for me. The synthetic stocks help but I still reset my hold down screw torques and finalized my zero's.

When hunting deer (the largest thing 've hunted) I never worried about accuracy that much and actually started hunting with a handgun. Easier to drag them out of the woods.

Groundhog on the other hand need a pretty good load/zero and a dope card. But we'd hunt them in fields that ranged from point blank to 1000+ yards.

Like I said I'm not calling anyone out or saying something is right/wrong. Merely stating that I prefer groups with more shots to get get the load I'm testing dialed in for the type of shooting I plan on doing.

 

[earlthegoat2]

A group to me, implies shooting shots in fast enough succession to not allow optimal barrel cooling.

This will give multiple shot accuracy.

I suppose one could shoot a group all from cold barrel with enough wait time between shots. I guess that would then be cold bore mechanical accuracy.

YMMV.

 

[AK Hunter]

When sighting in I work from a rest, that takes me out of the situation & three shot groups work well and also saves on ammo.
But like AJC1 said the shot from a cold bore is the one that matters, so after getting it dead center from the rest I let my guns sit & totally cool, then double check with the final cold shot. I have also seen a difference from a clean barrel to a fowled barrel in my one shot hits.

 

[forrest r]

Moderator's,

If this thread starts going south please shut it down!!!

It was never my intention to start anything/stir anything up. I simply started a thread on why I like more shots on paper, nothing more.

I'm glad others are responding with what they do and what there intended purpose is. Hopefully this gives others insight on what to do, what to expect. In these trying times with costs and shortages getting to where you want to be with a load.

 

[jmr40]

I don't see the tread going south. Just a discussion of the merits of how many shots are necessary.

Shot 4 different 10-shot groups

Even with reloading my own ammo I'm looking at about $1 every time I pull the trigger. I don't need to spend $40 on ammo in one range session to find out what I need to know.

Three shots fired in under 1 minute replicate real world hunting situations so 3 is plenty for me. I'm much more concerned about how far my 1st shot from a cold barrel impacts from my point of aim. If the next 2 are all within 1 MOA of each other I can live with that.

Of course if you participate in a shooting sport where more than 3 shots are necessary then you should train for the way you compete. Three shots give a pretty good indication of the load's accuracy. Groups of 5 tell you about the accuracy of the rifle. Ten or more shots start to tell about the concentration levels of the shooter and how well they can tolerate recoil.

Each has their place.

 

[kmw1954]

Well with my lowly Savage Axis 223 I can only load 4 rounds into the box magazine and then hand load one into the chamber for a total of 5 rounds and honestly it is a royal pain in the rear to top load one into this chamber with this magazine. Much easier and simpler to just load one into the mag, and load the chamber and then reload the mag. It's a lot of work. So I do not shoot 5 shot groups in my rifle.

Also if I am shooting accuracy test for the load or the gun I certainly am not going to base it on one grouping no matter how many rounds it is. I shoot multiple 3 round groups at multiple targets and then compare. If everything looks good I will repeat that same grouping on a completely separate day and then again compare to see if everything is repeatable

 

[westernrover]

Any firearm is only as good as it's worst shot/group.

Exactly. Therefore it (the firearm and cartridge combination) cannot be better than it's worst shot/group. A three shot group is very useful when it shows a problem. A 20-shot group is a complete waste of time if three shots are spread across 2 MOA, or if the ES is 150 fps, or if the velocity is 200 fps too low.

 

[AJC1]

I don't see the tread going south. Just a discussion of the merits of how many shots are necessary.

Ten or more shots start to tell about the concentration levels of the shooter and how well they can tolerate recoil.

Each has their place.

This is crazy important in games that have longer strings. A 6mmbr is nice and good for 60 shot courses. I cannot immagine a long string with a 300wm like some competitors do. At that point I'm the problem!!!!

 

[bigpower491]

When sighting in I work from a rest, that takes me out of the situation & three shot groups work well and also saves on ammo.
But like AJC1 said the shot from a cold bore is the one that matters, so after getting it dead center from the rest I let my guns sit & totally cool, then double check with the final cold shot. I have also seen a difference from a clean barrel to a fowled barrel in my one shot hits.

I do it pretty much like this myself.. Lead sled takes me out of it when im working up loads, then when i find something that i really like,, my next session with that load, ill let the barrel cool between shots then clean it. I know it's a bit of work, but I feel it best simulates my real world hunting situations....

 

[AK Hunter]

I do it pretty much like this myself.. Lead sled takes me out of it when im working up loads, then when i find something that i really like,, my next session with that load, ill let the barrel cool between shots then clean it. I know it's a bit of work, but I feel it best simulates my real world hunting situations....

I have found that if I shoot from a clean bore my first shot is way off. Most of my guns I shoot from a fowled barrel, it's dead center then. If I shoot it in from a clean barrel any follow up shots are going to be off. So just before any accurate shooting or the day before hunting I shoot one or two shots through them, then all my shots are good.

 

[fxvr5]

Some readers might find this article of interest;

https://www.ssusa.org/articles/2019/9/25/accuracy-testing-shortcomings-of-the-five-shot-group/

 

[JFrank]

IMO three shot groups during load development is just fine, sometimes I only shoot two.
Point is if two shots are bad/ big then why shoot a third? It won't get smaller...