Gun magazines testing for accuracy. Larger round counts.

bricz75

New member
In the various gun magazines, they typically shoot 3 rounds to report on accuracy. Why don't they also shoot strings of more than 3 rounds so a person can see how accurate the rifle is when the barrel heats up?
 
I think it's largely because most hunting guns (light weight barrels) are seldom fired more than three quick shots in field conditions

Another reason is you can almost always maintain a smaller group for just three shots, and everyone likes small groups.

They don't want to face the reality the gun isn't consistantly that accurate

A good way to determine the true accuracy is to shoot multiple targets over multiple days, putting new ones directly over, and precisely aligned with the previous targets.

Then you have a record of individual groups under different conditions ,and the first target is an aggregate of all the groups.

Most hunters are mainly concerned more with where the first couple of shots from a cold barrel will go
 
Three reasons; in my opinion.

* Most folks feel 3 shots in a group is good enough to realistically (statistically?) show what the stuff's accuracy is.

* Many rifle makers guarantee some accuracy level to no more than 3 shots because their rifles aren't made good enough to sustain good accuracy for any more shots as the barrels heat up.

* It's cheaper and takes less time than shooting more shots.
 
3 shots gives a better chance of getting a small group. The makers of the guns being tested are most likely advertisers in the magazine.

Small groups = happy advertisers.
 
Statistically, I think the odds of shooting the smallest 3-shot group are the same as shooting the largest one. The bell curve of 3-shot groups is shaped the same on both sides of the average one.
 
Statistically, the odds of shooting the smallest 3-shot group are the same as shooting the largest one.
The point is each additional shot beyond three increases the odds of the group becoming larger.

Nothing can make it smaller than the first three
 
Three is plenty enough to know the accuracy of the rifle. Any more and you are increasing the odds of the SHOOTER messing up, not the rifle. I have no interest in knowing how my rifle shoots with a hot barrel. I won't be shooting at anything with a hot barrel anyway.
 
Anything beyond ONE shot statistically increases the odds of enlarging the group. :D

It's no great conspiracy & has zero to do with advertisers.

In my case, I used to do 5-shot 100-yard groups with rifles.
Then Obama came along.
Ammo became harder to get.

I've done my centerfire rifle testing with 3-shot groups for some time now for two reasons:
Stretches the limited ammo supply & it does cut down on the shooting time.

There are a number of factors involved in producing an average gunmag article, one of which is having something to shoot through a given test gun, another is the time involved.

That time has to be balanced out, for those of us who operate as a for-profit entity & not just as a hobby.

Freelance checks are not large, and with the associated costs involved that cut into the profit margin on any article sale, time management is important.
Spend a hundred hours in production & end up with a net pay rate of $5 per hour, why bother?
Would YOU work for $5 per?

3-shot groups are enough to give an idea of what the rifle can do.
In a hunting scenario, you're unlikely to blow off more than 3 rounds at any particular animal.
On a battle rifle, pinpoint accuracy isn't a factor & it's irrelevant in the broad picture if groups will open up an inch or so as the barrel heats up with extended firing.
And so on.

With 3-shot groups I use less ammunition (more left for the next gun), and I spend less time.
Nowdays, my testing is about half of what it used to be, round-wise, across the board because I just can't get the quantities I used to get.
Increasingly, I'm also doubling up in shooting sessions, doing two or more guns, which makes time management even more of a factor.
For many years I was able to get most of my testing done on the hillside 3 miles from my house.
When damfool yokels trashed that private properly so badly the owners posted No Shooting up there, I now have to drive a 35-mile round trip West for handguns or a 35-mile East round trip for most rifles.
Time adds up.

Most don't understand this is a business, not just a casual unstructured Load-Em, Shoot-Em, Go-Home deal.
Neither ammunition nor time is available in infinite amounts.
Gas prices are not what they used to be.

I'd imagine other writers are going pretty much the same route for pretty much the same reasons.
Denis
 
jmr40 (and others, too), if three is plenty enough to know the accuracy of the rifle and any more and you are increasing the odds of the SHOOTER messing up, not the rifle, consider the following questions....

What about testing ammo, or a component thereof, wherein the shooter is not the aiming and holding part of the shooting system? Is a single 3-shot group good enough to represent how 99% of that ammo will perform?

Are the first three shots of a given load tested always the same size group?

What's the size of the group produced by the first three shots fired in the 270-shot, 600-yard test group of M118 7.62 NATO Nat'l Match ammo shown about 7/10ths the way down in the following:

http://www.ar15.com/mobile/topic.html?b=3&f=16&t=512887
 
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It's an imperfect system, as I've pointed out many times.

View any printed mag write-up as an introduction to the product, not an intensive lab analysis.

You want more, buy the gun & do it yourself. :)
Denis
 
"You want more, buy the gun & do it yourself.

Exactly! Which brings up another point. Seems like most posters on the web all own half minute rifles yet the writers in the gun rags almost never seem to even get one inch groups. :eek: Either they're getting lousy guns or they can't shoot worth a darn. ;) Seriously, I do know the difference between a rifle that been tweaked and played with to deliver tight groups and a straight out of the box factory made rifle. I have a Ruger M77 RSI that after two years of load work will only shoot 1.25 to 1.50" groups. I got it cheap because the previous owner could only get 4.0" groups from it. On the other hand, a Winchester M70 XTR I picked up at a gun show does .50" with Winchester 150 gr. Power Point factory ammo. The rifle is out of the box stock. Just a gun I bought on a whim.
Just how much accuracy does the average hunter need to hunt big game? I'm lucky enough that most of my rifle do better than that but 1.5" consistently is where I draw the line. Any deer or elk and even antelope within 300 yards is in serious trouble from any of those rifles.
Paul B.
 
3 shots is the smallest number needed for a group with a geometric center that can have an area measurement. One shot gives you a point, two shots gives you a line, three shots defines an area.

While one shot is all that is required to zero an optic (if you know how to do it and have the equipment necessary to do it), 3 shots is the minimum for adjusing a scope or iron sights to zero with the procedure most shooters are familiar with.

More shots only gives you more statistical data about how that rifle, shooter, and load are performing at that time. Since Gun Rag Writers are either reviewing a gun, or a load, then it stands to reason that they would gather enough information to fill their alloted article space without wasting much effort for paragraphs and pages that will end up on the cutting room floor.

After all, a serious ballistics report on a load involves pressure traces, barrel timing analysis, port pressure if in a gas operated semi auto, and all sorts of other stuff that has nothing to do with the bullet actually impacting a target.

So I'm not saying that the writers are writing for a stupid audience, just that for the purposes of selling gun rags, 3 round shot groups seems to be doing just fine.

Jimro
 
Space is another consideration.
Trust me- it AIN'T the writer who decides how long a given write-up is going to be. :)
Denis
 
What's a "barrel timing analysis" and what does it measure? Never heard of such a thing.

Is it the time from firing pin's first touch on the primer cup to when the bullet's heel leaves the muzzle?
 
Bart B.,

Yes, how much time the bullet spends in the barrel after the firing pin drops until exiting the muzzle, so the act of measuring that is "timing" as a verb, the act of measuring the time. I'm sure there are other synonims for it in the realm of internal ballistics.

My point was that very few articles ever address internal ballistics, mainly focusing on external and terminal ballistics.

Jimro
 
Most people couldn't care less about the level of technical detail involved in internal ballistics.

Little interest, no room.
Denis
 
DPris,

My point exactly, writers aren't going to waste their time on something that doesn't make their article more of a selling point for their editor.

Every so often you'll see a reviewer who dissassembles enough rounds to get a small sample size of charge, bullet, and primed brass mean and standard deviation. While interesting to me, I don't expect most people to care about consumer level quality checks.

I once was forwarded a job opening position for a gun writer job by someone who thought it would be a natural fit for me. The job reqirement was 8 articles a week. That would literally be a full time job for anyone, and I don't see how I could do any sort of thorough research on 8 different firearms or ammunition loads every week.

Jimro
 
Jimro, I agree that's when the clock starts. 1/8000th second later, the muzzle 24 inches away starts to wiggle and the primer fires. 1.2/1000th second later the bullet exits somewhere in that wiggle cycle.
 
I can't see how anybody could pull off 8 a week, with any depth whatever.

My max was 7 a month & that kept me very busy. :)
Denis
 
There was a time when most gunwriters were familiar with, or competed in, NRA rifle competitions. The typical group is either 10 rounds, for rapid fire sitting and prone, or 20 rounds prone long range. If you shot small bore prone, you shot 20 shots for record on each target, though that is four 5 shot bulls at 50 yards and two ten shot bulls at 100 yards. There are good reasons to spread the shots out in small bore, it becomes impossible to distinguish between hits at greater shot counts.

So, there was a time when you expected to shoot 20 round strings, and shooters understood that consistency was a quality attribute. It is also very hard to shoot a 1 MOA group, or less, with 20 shot groups, or even 10 shot groups. Inaccurate rifles and ammunition combinations simply cannot shoot tight, high shot groups.

The idea that a "bad" shot is just as likely as a "good shot" assumes that each shot will have the same potential offset from the center. I do not believe that is true. When you are talking about normally distributed groups, shots far away from the mean would be things that have a chance of 1:100, or 1:1000. You have to fire enough shots to determine a meaningful mean and standard deviation, but remember ,

68% of the distribution lies within one standard deviation of the mean.
95% of the distribution lies within two standard deviations of the mean.
99.7% of the distribution lies within three standard deviations of the mean.

Small shot groups are less likely to pick up a three standard deviation data point.

While it is true that lightweight barrels start to "walk" once they heat up, that does not preclude waiting between shots for the barrel to cool down. Given enough cooling time, even a ten or 20 shot group can be fired from lightweight hunting rifles, which would provide a much better estimate of the true accuracy of the rifle, than three shot groups. Two points define a line, three a plane, but three shots do not determine much of anything else.

I can say even five shot groups can be deceptive. I have been running tests on my FN 270 Win, developing loads with five shot groups, and if they have promise, shoot large groups to test the hypothesis. Recently I shot a really nice tight five shot group with 130 Fed Fusion's and WC852. I really thought I nailed it. Then I shot a 20 round group with that load. Not awful, not great, nothing to crow about. Now, if I had left well enough alone and not shot that 20 round group, I would not have learned the load was so-so, but I would have been happy living in my delusion.

It is my opinion that the three shot groups that gunwriters publish reveal little to nothing about the true accuracy of the load, or the rifle. One very prominent gunwriter shot three shot 30-30 groups, out of his lever action Marlin, most I think were cast bullets, and the guy was claiming sub MOA groups. I am of the opinion that this is the Texas Sharpshooter fallacy http://www.fallacyfiles.org/texsharp.html. This gunwriter does not have a sub MOA Marlin, he has not fired enough shots to shot the true accuracy of the thing. A competitive shooter would know that accuracy comparisons based on three shot groups would be totally spurious, because he had shot enough groups to know that three shots are not enough to determine whether a load is accurate, or just a statistical fluke.

There are a number of good reasons why gunwriters don't thoroughly wring out firearms under test. The first is that it is a lot of work. The second is that a through shooting test might reveal that the firearm is a dog, something which the advertiser does not want to be known, (it is just as likely that the gunwriter is not a very good shot anyway) Plus the fact, that gunwriters are not compensated because they can shoot small groups, future commissions depend on the sales bump his article provides now.
 
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