Gunsmithing True Accuracy Of A Rifle - Whats Your Take???

[EXSOCAL]

Chances are this will start a shit storm of some sort or another but I figured I would post this up and get some opinions.

My buddy and I go back and forth about accuracy claims and what they actually, truly mean. You see everyone and their uncle these days who makes these truly magnificent accuracy claims about their custom, semi custom, and factory rifles.

My take on it is this: <span style="text-decoration: underline">MOST</span> any rifle around these days, made through the use of modern machining techniques with decent quality parts by a smith who can read the dials on a lathe or mill, can produce a sub MOA group at one point or another. You strap a bone stock, bottom of the line, Rem. 700 to a lead sled and shoot enough groups down range and the chances are you could print some awesome sub half or sub quarter MOA group when the moon, stars and Justin Beiber all come into alignment, no telling how many rounds or groups it would take, but it surely is possible. Does this make this a 1/4 MOA rifle. Hell naw. Not in my opinion.

When someone makes a claim of having a half MOA rifle, I would assume that this means that on any given day of the week, this rifle could print 10 groups or so that would average this accuracy claim. In reality, I have a feeling that there are very few rifles that could actually stand up to the claims and produce this claimed "accuracy" on a consistent basis. I realize we all have bad days shooting which throw are groups off, bad weather, etc. I'm talking good conditions, from your preferred shooting position, good ammo, good glass, etc.


So my question to you all:

In your opinion, what does it take for a rifle to be a true "xx" MOA rifle - just one group every so often??? Consistent groups below this number? 3 shot groups?? 5 Shot groups???

 

[Tyler Kemp]

Re: True Accuracy Of A Rifle - Whats Your Take???

If you're shooting every 3 shot group under half minute, it wouldn't matter if it was 5 shot groups, or 100 shot groups, because every shot would all be under half minute. To call some a "x" minute gun, I think anywhere from a 3-5 shot group is sufficient if you can do it repeatedly.

 

[EXSOCAL]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tyler Kemp</div><div class="ubbcode-body">If you're shooting every 3 shot group under half minute, it wouldn't matter if it was 5 shot groups, or 100 shot groups, because every shot would all be under half minute. To call some a "x" minute gun, I think anywhere from a 3-5 shot group is sufficient if you can do it repeatedly. </div></div>

Agreed.

 

[sandwarrior]

Re: True Accuracy Of A Rifle - Whats Your Take???

moa accurate, or better rifle:

Consistent groups of under "XX" moa @ a given range when conditions are ideal.

Accurate shooter:

Someone who, knowing the limitations of their rifle, (or lack thereof, because it's a really precise rifle) can place a bullet within the prescribed moa on a consistent basis in any reasonable, but adverse, condition (not ideal).

IMO, no. I agree with you. Most 'off the shelf' rifles will not do this. I have found that Savage varmint/LE/LR will. Many better Rem 700's will do this also. A custom gun built for that HAD BETTER do that.

If I take a rifle out on a consistent basis and produce sub moa groups in ideal conditions, then it's up to me to produce those same groups in less than ideal conditions. Or don't call myself a great shot.

 

[jrm850]

Re: True Accuracy Of A Rifle - Whats Your Take???

I get where you are coming from... For me consistency builds confidence. I would rather have a rifle that shoots in the 7s all day in any condition than a finicky rifle that's a one holer only when things are perfect. I want to know what to expect and be able to just keep pulling the trigger.

 

[TOP PREDATOR]

Re: True Accuracy Of A Rifle - Whats Your Take???

ditto on the above 2 posts.

consistancy and accuracy gets confused alot, though it's a fine line between the two.

just as above, i'd rather have a rifle that always shoots not so great but repeatable groups compared to one that does it most of the time leaving some of the time to chance.

i never like the saying "only accurate rifles are interesting".....actually they are kinda boring shooting the same hole most of the time.

 

[Mod Adahy]

Re: True Accuracy Of A Rifle - Whats Your Take???

I would argue the above posts. 3 or even 5 shot groups are not enough to qantify a "moa" rifle. What if I go and shoot 3 3 shot groups and all are under 1/2 minute? Is that sufficient information to quantify a 1/2 moa rifle? That fills your requirement of every group I shot under the said claim. I think you will find most guys use a minimum of 5 10 shot groups to confirm, and even then, it is not hard and fast. Lets put your test to the test, shoot one 100 shot group and tell me if it is still under your said claim.

 

[Tyler Kemp]

Re: True Accuracy Of A Rifle - Whats Your Take???

It was more of a theoretical statement...imagine 33 3 shot groups, under 1/2 moa. If you overlap them, essentially it should show one big hole in the target. Disregarding a lemon bullet, case, etc, there's no reason if you have a true 1/2 moa rifle that every bullet won't go within 1/2 moa...

 

[EXSOCAL]

Re: True Accuracy Of A Rifle - Whats Your Take???

I would agree with all the above for the most part. If a rifle is a true 1/2 MOA rifle, then theoretically, in ideal conditions, ten 5 shot groups under half MOA should be the same as one 50 shot group.

I've heard people who only use 3 shot groups to judge accuracy make claims that anything greater tends to exhibit more shooter skill and error than true accuracy potential. I could never really agree because even if you have a rifle in your possession that will put every single bullet through the same hole, yet only groups 1/2 MOA consistently with you shooting it, then you have a 1/2 MOA rifle, not a "one hole" rifle. Yes? No? Maybe? That adds another dimension to it, is the shooter capable of wringing every little bit of accuracy out of a particular rifle??? Without clamping an action down in vise and firing round after round in a controlled manner in a controlled environment, how do you ever know? I know my personal capabilities and limitations and when I shoot to those levels and usually if a rifle can meet those levels consistently, I'm happy.

 

[sandwarrior]

Re: True Accuracy Of A Rifle - Whats Your Take???

Lets look at it another way. I have a K-31 that I took to the range a month or so ago. At the range I have four friends there who are often there, and that's how we became friends.

So, having worked up my best 7.5x55 from my K-31 load I could, from the bench I checked the zero at 100, 300, and 500 yds. All good. I then raised up the sight to 900 (900m= 990 yds.) and fired. The bullet struck center mass on the 1k gong. I then shot two more and they both center punched the 1k.

I then had Charles shoot the rifle on a three shot shot group at 1k using the same hold as I did. He center punched it all three times. Tom was there, he did the same thing. Bo was the last and he shot five into the center target.

Then, as a comparison, I brought out the GP-11 ammo and checked it. High. I dropped the sight to 800 and instead of holding 6 o'clock held dead center. I center punched the gong again. Next was Charles who center punched it. I fired again and missed. But, I called why. Then fired the last shot and hit.

All told that was a lot of hitting by different people at 1k. Conditions were pretty good. Wind calls minimal. Generally, the rounds mostly went into about a 2 moa or 21" group @ 1k.

What I mean about an accurate rifle is four people got behind it and were perfectly able to ring the gong @ 1k. That is an accurate rifle. Accurate shooting was those that needed to made slight wind adjustments. And, the sights had to be adjusted and an aimpoint figured out so the GP-11 could work as well.

Obviously not a 1/2 moa gun, but we weren't shooting @ 100 yds. with a scope either. I think that kind of rifle accuracy is very telling.

 

[E. Bryant]

Re: True Accuracy Of A Rifle - Whats Your Take???

Firing many groups with a small number of shots per group is <span style="font-style: italic">not</span> the same as firing one group with a large number of shots. This is because we measure the extreme spread of each small group, but we do not look at the deviation of the center of one group relative to the point-of-aim, or the center of the next group (each group is unlikely to be centered at the same location on the target, but this error is ignored in the typical process of firing and measuring groups).

One also has to ask what we want to know when stating the accuracy of a rifle - do we mandate that <span style="font-style: italic">every</span> shot fall within the claimed limit, or just that a statistically-significant number will fall within the limits of the claimed accuracy?

Some additional interesting reading:

http://www.the-long-family.com/Group%20size%20statistical%20analysis.pdf

 

[z28kid]

Re: True Accuracy Of A Rifle - Whats Your Take???

This is just my opinion, but on the groups of ten or more shots other factors come into play. For instance if you break cheek weld to reload, firing rapidly and heating the barrel, or my biggest enemy... seeing a good group develop and getting excited to the point of pulling one.
I do think that if you fired Ten 5-shot groups that all were below or averaged less than .5 moa, its a .5 moa rifle.

 

[Robert Gradous]

Re: True Accuracy Of A Rifle - Whats Your Take???

Is it the Indian or the arrow.

 

[sandwarrior]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: z28kid</div><div class="ubbcode-body">This is just my opinion, but on the groups of ten or more shots other factors come into play. For instance if you break cheek weld to reload, firing rapidly and heating the barrel, or my biggest enemy... seeing a good group develop and getting excited to the point of pulling one.
I do think that if you fired Ten 5-shot groups that all were below or averaged less than .5 moa, its a .5 moa rifle. </div></div>

I think you and Robert Gradous are getting back to the Indian/arrow thing when what I try to break down is 'Just the bow and arrow' Forget the 'Indian' for now.

And accurate rifle is a rifle you can count on to go out on any given day and shoot <span style="text-decoration: underline"><span style="font-style: italic">within</span></span> the confines you set for it, i.e. one moa, 1/2 moa, 1/4 moa, etc. The rifle has to be able to produce it's given accuracy on any given day that that it could be naturally attained. I'm trying to boil down rifle consistency. That has to be combined with ammunition as well. An accurate rifle has to be fed good ammo.

It always seems this discussion always gets intermingled with how a shooter can shoot. For example, in high, gusting, winds the best you can shoot is 3.5 moa @ 200 yds. Normally in calm winds you shoot .5 moa @ 200 yds. Does this make the rifle a 3.5 moa shooter? Not hardly. It means the shooter needs wind practice. But at least he's practicing with a 1/2 moa rifle instead of a 3.5 moa rifle. Because the big spread certainly isn't the rifle's fault.

We need to learn separation of human function from mechanical function. The rifle and ammunition is mechanical. Obviously, how we shoot is human. Anything pertaining to how a human lost accuracy should be blamed on the human not the rifle. How well a rifle can be made to shoot, is usually more the human getting up to the rifles ability.

 

[buckey]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robert Gradous</div><div class="ubbcode-body">Is it the Indian or the arrow. </div></div>

+1

 

[mark5pt56]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Eric Bryant</div><div class="ubbcode-body">Firing many groups with a small number of shots per group is <span style="font-style: italic">not</span> the same as firing one group with a large number of shots. This is because we measure the extreme spread of each small group, but we do not look at the deviation of the center of one group relative to the point-of-aim, or the center of the next group (each group is unlikely to be centered at the same location on the target, but this error is ignored in the typical process of firing and measuring groups).

One also has to ask what we want to know when stating the accuracy of a rifle - do we mandate that <span style="font-style: italic">every</span> shot fall within the claimed limit, or just that a statistically-significant number will fall within the limits of the claimed accuracy?

Some additional interesting reading:

http://www.the-long-family.com/Group%20size%20statistical%20analysis.pdf

</div></div>

Very good read, thank you.

 

[jrm850]

Re: True Accuracy Of A Rifle - Whats Your Take???

RE: confidence/accuracy-

I used to work up handloads for rifles before I delivered them to the customers. It was generally enough time to get a rough feel for the rifle and how it handled hot barrels etc. They would all be capable of good groups but when it came time to deliver the rifle at the range, some of them I would sweat squeezing off number 4 and some of them I just knew I could go to 10 if I wanted. Those were the rifles that made me happy.

 

[Greg Langelius *]

Re: True Accuracy Of A Rifle - Whats Your Take???

I shoot groups for only one reason; to find out whether a tweak is working better or worse.

IMHO, scores count, groups don't.

Greg

 

[EXSOCAL]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">I shoot groups for only one reason; to find out whether a tweak is working better or worse.

IMHO, scores count, groups don't.

Greg </div></div>

Agreed.. But... good scores are somewhat a result of a rifle that has the potential to post good groups, ya?

 

[andrews1958]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Buckey</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robert Gradous</div><div class="ubbcode-body">Is it the Indian or the arrow. </div></div>

+1</div></div>

++1

 

[Straight Shooter]

Re: True Accuracy Of A Rifle - Whats Your Take???

Four 3 shot groups shot in succession. Four different loads 338 Lapua.
Brand new barrel. No break in just centered close enough for group testing with 2 shots and then went to these four groups.

This one passes.

Top right is 94 grains Retumbo
OAL 3.9
300 grain Berger bullet
Fed 215 primer
Lapua new unprocessed brass.

 

[Papagrizzly]

Re: True Accuracy Of A Rifle - Whats Your Take???

In my opinion, and with a lot of testing experience with many calibers and custom guns made by a World 1000 yard record setting gunsmith, three shot groups give you a flavor, but do not tell the story.

Most people test at 100 yards. If you were to shoot 4 groups of at least 5 shots each, and each of those groups was under 1/2 an inch, then you can say that you have a gun that can duplicate that accuracy fairly well. Now, if you test at 300 yards and beyond, like I do, then you can really tell whether you have a good barrel, a good load, and your gun likes what bullets/powder you are feeding it.

There are many factory rifles capable of shooting 1/2 MOA easily. The problem sometimes is that the shooter feeds the wrong type of ammo or inconsistently loaded ammo and then blames the gun. Well loaded ammo is critical to a gun's accuracy, so is the barrel and proper chambering etc. Last, but not least, consistent trigger control and release, plus consistent cheek pressure on the stock etc. all play a part in group size.

 

[Straight Shooter]

Re: True Accuracy Of A Rifle - Whats Your Take???

Papagrizzly,
This was just the intial test fire to proof the chamber before coating. Real load development comes once it is complete. This one will judged be on multiple 5 shot groups at 500 yards.

Next time you talk to your 1000 yard smith you might ask him if he knows a promising young lad named Brady. This is one of but many Brady has turned out since visiting Missouri. The method works. 21 year old eyes don't hurt either.

 

[EXTREMEPREJUDICE]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SOCAL</div><div class="ubbcode-body">

So my question to you all:

In your opinion, what does it take for a rifle to be a true "xx" MOA rifle - just one group every so often??? Consistent groups below this number? 3 shot groups?? 5 Shot groups??? </div></div>
Well, the question is how many groups does it take for the "shooter" to best be able to reveal the rifles potential. A 1/2 MOA rifle will send the projectile 1/2 MOA from the POA every time that it is fired. The reason it may not shoot a 1/2 MOA group will depend on external factors mostly environmental but to include; load, projectile, time of flight, wind, etc. and last but not least shooter error. A 1/2 MOA group indicates the rifle shoots 1/2 MOA and all other influences including the shooter are PERFECT (I have always doubted this to be possible until I saw that video of LowLight managing the recoil of that .338 Lapua.........a totally different level) or a combination of variables conclude with a 1/2 MOA result. Rifles that shoot 1/2 MOA groups are actually much better than 1/2 MOA because the result includes not only the rifles performance but also the combination of external factors (which of the greatest is shooter error.) I always have a chuckle when guys post results of shooting groups of less than 1/2 MOA at 1000 meters, mostly with a new rifle or their first time at that distance. Perhaps a handfull of shooters on the planet can be that good?

 

[Papagrizzly]

Re: True Accuracy Of A Rifle - Whats Your Take???

Staright Shooter - Your groups are amazing for a new gun that was not broken in. I'd jump on that one hole gun

If Brady was one of Gordy's students, he has learned from the best. I get pretty excited when I see a new gun shoot like yours, and that's before doing any serious load development. You have a photo of the whole gun?

 

[Straight Shooter]

Re: True Accuracy Of A Rifle - Whats Your Take???

It was raining so we just shot a couple before we left.

 

[EXSOCAL]

Re: True Accuracy Of A Rifle - Whats Your Take???

Nice stick StraightShooter!

All good responses, interesting discussion at the very least.

 

[Papagrizzly]

Re: True Accuracy Of A Rifle - Whats Your Take???

SS - Beautimus Maximus!!

 

[DHDeal]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robert Gradous</div><div class="ubbcode-body">Is it the Indian or the arrow. </div></div>

With your rifles Robert, it is the arrow. I am just a decent "Indian", but shooting my 308 built by Robert, I am a minor Chief!

I personally think that a good shooter with a good rifle can replicate that 1/2" group time and again. That having been said, I have had hiccups that I cannot explain. Was it the bullet, me, wind, shadow/sun? I don't cull shots from a group, but a flyer now and again is only mildly irritating as I KNOW my rifles.

The rifle Robert built for me is as consistent as the sunrise and if it doesn't put them on call, well.....

FWIW, I usually consider 5-5 shot groups a pretty good indicator for a smokeless rifle. In my BPCR's, I usually will go with 3-10's. Don't know why, just works for me. Oh yeah, these will be over a chrono as I can get 2 pieces of info for the price of 1.

YMMV.

 

[dieselgeek]

Re: True Accuracy Of A Rifle - Whats Your Take???

Ammo comes into play here does it not?

 

[EXSOCAL]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dieselgeek</div><div class="ubbcode-body">Ammo comes into play here does it not? </div></div>

It does, however I think a fair accuracy test of a rifle comes with ammo that it is known to shoot well with, eg. good quality reloads, etc, not just any off the shelf boolit.

 

[Killer Spade 13]

Re: True Accuracy Of A Rifle - Whats Your Take???

Don't confuse accuracy and repeatability.

Accuracy is hitting the intended targer.

Repeatability is the bullet striking the same point each time.

You can have a rife that shoots a .01" group. Let us say that your intended point of aim is a circle 3 inches in diameter. If each shot misses the intended point of aim by 10" left and 20" inches high, it's not accurate worth a damn, although it's shooting a .01" group.

Conversely, if you have a rifle that shoots a 3" shot group, it is not as repeatable as the aforementioned rifle, but if it hits the intended point of aim each time, it is infinitely more accurate than the other rifle.

That for which we strive is repeatability AND accuracy.

 

[SPM]

Re: True Accuracy Of A Rifle - Whats Your Take???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jrm850</div><div class="ubbcode-body">I get where you are coming from... For me consistency builds confidence. I would rather have a rifle that shoots in the 7s all day in any condition than a finicky rifle that's a one holer only when things are perfect. I want to know what to expect and be able to just keep pulling the trigger.</div></div>

I don't quite understand this statement, and I'm not trying to call you out but here is my perspective. If your rifle shoots in the 7's in any condition maybe you have a sub 1/2 moa rifle and there is some inconsistency in your approach which is giving you a larger group. The only time a rifle is finicky it's about the ammo you feed it, but once you find what it likes it will repeat. So to me it's not how accurate the rifle is it's how accurate are you?

SPM

 

[dieselgeek]

Re: True Accuracy Of A Rifle - Whats Your Take???

So today I went to test my zero before my match. I've always wondered about cold bore, or if it's me being a cold shooter. Still that first shot, I felt like I was holding dead nutz on the bull. Anyway, I took that shot and then took 5 more and they landed above in a .262 MOA group. Hell even w/ the cold bore that's still right at .5 MOA.

Took one more shot to confirm I was .2 high and adjusted then took 3 more shots which landed in that lil bitty hole right by the bull. I called it good, and packed up. I'd say this gun is consistently under 1/2 min, if you work it or develop a load for it, I'm sure you could get 1/4 min consistently. Today the wind was so hard it was shaking the tables, and I feel my eyes blur when I spend to much time on the glass. That makes it hard for me to see the cross hairs right on the bull.

 

[jrm850]

Re: True Accuracy Of A Rifle - Whats Your Take???

Well I won't dispute that I am not the best shot in the world, but I have enough time behind a rifle to know when it is me. <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SPM</div><div class="ubbcode-body">
...The only time a rifle is finicky it's about the ammo you feed it, but once you find what it likes it will repeat. So to me it's not how accurate the rifle is it's how accurate are you?
SPM </div></div>
What I'm talking about are things like internal barrel stresses, Action stresses, bedding jobs, and tough to tune barrel Frequencies. Some barrels need a fouler after cleaning and some just don't seem to care. Some barrels need cooling time between shots and some don't. Rifes with peculiarities like these are what I consider finicky. Rifles like the superb one shown above with 4 different loads, all grouping and all having a POI within an inch of each other is the goal.
The .7s vs one hole was a hyperbole used to convey a point. obviously even a finicky one holer would still be capable of .7" groups.

 

[Graywolf.260]

Re: True Accuracy Of A Rifle - Whats Your Take???

Some basic principles of probability and statistics will help shed light on this question. It's not true that a ".5 moa" rifle should theoretically shoot sub .5 moa whether firing 3 or 30 times. That is a misunderstanding and is wrong because of the traditional way that the moa of a rifle is defined as the extreme spread for a group. Even if you reduce all the variances as much as you can (weight of charge, brass thickness, neck tension, cheek pressure, etc.)- you can't reduce them to zero. The actual variance in point of impact follows a Gaussian function and with enough shots you will see impacts that occur out in the tail of the Gaussian curve, because of physics and probability.

If we used standard deviation of distance from a point, e.g. the point of aim or geometrical center of the group, then as a larger number of shots are fired, (as long as there is no systematically increasing error as the number of shots increases due to e.g. barrel heat or shooter fatigue, etc.), the mean and standard deviation converge on their true values and give a more reliable indicator of the quality of the gun.