Bolt vs Semi accuracy groups.

[Falsecrack]

Gents (and ladies),

I'm hoping some of you folks might be able to help me answer something that I've been wondering about?

When making accuracy claims between gas guns and bolt guns, is it commonplace for the groupings to be 5 for the semi's and 3 for the bolts? For instance, when LaRue (just using this as an example and not trying to start a "versus" war) says that their OBR 7.62 is guaranteed a 1 MOA gun, it means that it can place 5 rounds inside an inch @ 100 yards. That much I get. But when GAP guarantees 1/2 MOA from some of their bolt guns, does this mean, by default, that they're talking about 3 round groups? I know too that some 5.56 semi's also use 3 round groups for their basis of accuracy claims.

 

[seanh]

Though I've seen many people and a few companies go with 3 shot groups, I thing industry standard is 5 shots regardless of bolt or semi. For those that only use 3 shots I'm wondering if it's due to the added difficulty of the 2 extra shots...they don't want a bunch of returns due to human error. For what it's worth, everyone I've every shot with, known etc. has always gone by 5 shots, regardless of gun type, semi/bolt; goes to pistols too semi, single shot, revolver.

 

[Grasshopper308]

Maybe they are cheap heads and don't want to burn that exta 30 cents to 5 bucks per round?? I like doing 100 shot groups because it's what the kewl kids do yo!

 

[Pointman308]

For me-3 shots for tactical rifles or field guns. 5-Shots for Benchrest rifles.

 

[Temp9]

3 shot groups are statistically invalid, in my opinion. I stopped shooting 3 shot groups after I shot a sub .25" 3 shot group at 100 yards with Tula .223.... I normally have problems staying on a paper plate with that crap. That group was simply a statistical anomaly that says nothing about the rifle, shooter, or ammo. Such anomalies are far less common with 5 shot groups. Even less so with 5 5-shot groups.

 

[stan462]

The LRUE OBR ARE SHOOTING SUB MINUTE.

 

[Ragincajun1919]

I think the minimum group size for a MOA claim should be 5 rounds, 10 is better.

 

[damoncali]

What's common is for companies to use the smallest number of rounds in the most selective manner they can get away with to make their products look good. What's reasonable is to look at what your goals are and pick a statistically valid number that will help you evaluate whether or not the rifle meets your needs. It is very rare for a manufacturer or gunsmith to make this sort of claim.

Group Statistics

The above page details how confident you should be in a rifle's accuracy depending on the number of groups you shoot and how many rounds each group consists of. Skip to the bottom section if all you care about is the results, which are sort of counter-intuitive. Shooting 6 7-shot groups will give you the same level of confidence as 5 10-shot groups, for example. A handful of 3 shot groups is basically worthless. It turns out the optimum group size is 6 or 7.

Of course if you're willing to measure deviation from center for every round, the more the better. But that is a huge pain in the ass.

 

[G60]

When making accuracy claims between gas guns and bolt guns, is it commonplace for the groupings to be 5 for the semi's and 3 for the bolts?

No. Without getting into the debate and politics of how many shots in a group most accurately represent a rifle and ammo's accuracy, and who chooses to do what, it's up to whoever's shooting the gun.

Personally, I choose to shoot 5-shot groups, regardless of rifle.

 

[M40_A1]

I stopped counting on 3-shot groups a long time ago. The military uses 10-shot groups for standards testing (don't know that they always do, though).

 

[Capt Academy]

I agree with G60. I personally shoot a few 3-shot groups in a roll on my tactical rifles and large caliber rifles, but also shoot the 5 shot groups as well. It just depends how I feel. The rifles accuracy does not seem to change, at least for me.

 

[Genin]

I only ever shoot groups if I'm doing load development or have changed something on the rifle and want to make sure accuracy has not been affected, I really don't see the point of them otherwise, I think hitting what you're aiming at is far more important. It's become a pet peeve of mine that people will brag about a 1/2 MOA group that is 4" off the mark of where they should have hit. Ridiculous. That being said, when doing groups I use 5 shots, however 3 shots to 5 shots doesn't seem to change the accuracy for me.

 

[matchman]

4"in is quite a bit but it really does not matters as its just a matter of adjusting the scope. When group shooting you do not want to shoot out your aiming point.

 

[TRTAC]

I also prefer 5 shot or more for testing. Three shots could be a fluke....... 5 or more means you meant to do that...

 

[Delta4-3]

I use One shot groups if I want to brag, but I'll average multiple 5 shot groups to determine a particular rifles potential, regardless of operating mechanism.

 

[samnev]

I use One shot groups if I want to brag, but I'll average multiple 5 shot groups to determine a particular rifles potential, regardless of operating mechanism.

Same here.

 

[T2CH]

So if I set up five targets and center punched each target wiht one round, did I just shoot an equivelant one hole five shot group?

If I can hit the target with one shot, why do I need to shoot the other four times?
Give me multiple targets, more fun.

I do however shoot groups to check potential every once in a while.

Where did the smilies go?

 

[bm11]

Larue no longer uses 5 shot groups for the test target. They switched to 3 round groups a bit back. KAC commercial rifles ship with a 5 round test group.

Gents (and ladies),

I'm hoping some of you folks might be able to help me answer something that I've been wondering about?

When making accuracy claims between gas guns and bolt guns, is it commonplace for the groupings to be 5 for the semi's and 3 for the bolts? For instance, when LaRue (just using this as an example and not trying to start a "versus" war) says that their OBR 7.62 is guaranteed a 1 MOA gun, it means that it can place 5 rounds inside an inch @ 100 yards. That much I get. But when GAP guarantees 1/2 MOA from some of their bolt guns, does this mean, by default, that they're talking about 3 round groups? I know too that some 5.56 semi's also use 3 round groups for their basis of accuracy claims.

 

[cramey74]

This is the only group that matters.

 

[JB02]

This is the only group that matters.

Indeed! Well said

 

[James n TN]

Really? I've gone thru arguments many times of 3 shot vs 5 shot groups and can you explain how 5 shot groups show you more over 3 shots?
My example if three shots shoot verticals or some crazy strung out group the next two shots don't make it any smaller. Shooting three shot load developments over a chronograph has served me well in the past and I stand behind load developing three shot groups for accuracy. I just back those loads up for consistency once I do find my sweet load. Of course I didn't shoot three IBS world records in the same year by the 3 shot load development that so many say is inaccurate oh but wait I did shoot those records. So please enlighten me and the rest your professional opinion and results on why three shots testing isn't better than five shots?

Since I'm not as active at postings on here as several of you are below is a link to an interview on my records and load developments.

Tennessee Tack-Driver

3 shot groups are statistically invalid, in my opinion. I stopped shooting 3 shot groups after I shot a sub .25" 3 shot group at 100 yards with Tula .223.... I normally have problems staying on a paper plate with that crap. That group was simply a statistical anomaly that says nothing about the rifle, shooter, or ammo. Such anomalies are far less common with 5 shot groups. Even less so with 5 5-shot groups.

 

[Temp9]

Really? I've gone thru arguments many times of 3 shot vs 5 shot groups and can you explain how 5 shot groups show you more over 3 shots?
My example if three shots shoot verticals or some crazy strung out group the next two shots don't make it any smaller. Shooting three shot load developments over a chronograph has served me well in the past and I stand behind load developing three shot groups for accuracy. I just back those loads up for consistency once I do find my sweet load. Of course I didn't shoot three IBS world records in the same year by the 3 shot load development that so many say is inaccurate oh but wait I did shoot those records. So please enlighten me and the rest your professional opinion and results on why three shots testing isn't better than five shots?

Since I'm not as active at postings on here as several of you are below is a link to an interview on my records and load developments.

Tennessee Tack-Driver

Let me begin by saying my opinion is far from professional. I will also say that a 3-shot group is far better at telling if a group does NOT work, than if a group does work. If the first 3 shots group like crap, then two more shots isn't going to help. On the other hand, you may get lucky and stack the first 3 shots (possible no matter how crappy the gun, stacking 3 shots in a row is possible), but the next two should show you a more true representation. It is arguable that it is also possible to stack 5 shots with a crappy gun, and this is most definitely true, but far less likely. The bottom line is that a higher sample size results in a better confidence interval and lower standard deviation in group size (standard deviation of extreme spread).

Additionally, as a benchrest shooter, you are at a statistical advantage when shooting low sample size groups (ie. 3 shot groups). The confidence interval will improve when your sample standard deviation decreases (ie. if you have a more accurate rifle). Most of us here are not capable, nor are our rifles, of grouping consistently in the teens. Therefore, we must make up for this by increasing group size to at least 5 shots. What works for BR does not work for field rifles.

I'm sure my statistical rambling is a bit off, and someone will be in to correct me shortly. It's astonishing how much I've forgotten in two years. I hated that class, but I'll be damned if it wasn't one of the most useful classes I've taken.

By the way, I remember reading that article quite a while back and wanting to get into benchrest. If I had any money back then, I would have probably taken up BR instead of whatever the hell it is I do now. Very impressive accomplishments on your part, to say the least. I'd shake your hand, but I'm afraid I haven't figured out how to do that over the internet, yet.

 

[FALex]

I remember when the Hide had the rule about not posting shit about groups unless they were 5 shots, minimum. Since reading that, I could never shoot a 3 shot group and feel good about it. Damn site...giving me a complex and all that!

 

[bodywerks]

Gents (and ladies),

I'm hoping some of you folks might be able to help me answer something that I've been wondering about?

When making accuracy claims between gas guns and bolt guns, is it commonplace for the groupings to be 5 for the semi's and 3 for the bolts? For instance, when LaRue (just using this as an example and not trying to start a "versus" war) says that their OBR 7.62 is guaranteed a 1 MOA gun, it means that it can place 5 rounds inside an inch @ 100 yards. That much I get. But when GAP guarantees 1/2 MOA from some of their bolt guns, does this mean, by default, that they're talking about 3 round groups? I know too that some 5.56 semi's also use 3 round groups for their basis of accuracy claims.

No. Especially not with GAP. Tyler Kemp has posted several videos as a rep for GAP. Several videos include not only 5 shot groups, but several, consecutive, 5 shot groups. This includes their GAP10, their semi-auto precision rifle.

 

[G60]

Really? I've gone thru arguments many times of 3 shot vs 5 shot groups and can you explain how 5 shot groups show you more over 3 shots?

I see your point, and I see Temp9's point as well.

Regardless of the number of shots or groups, I think it all boils down to whether or not the shooter is shooting the group to accurately assess the performance of their setup, or if they're shooting the group to cherry pick, post pics on the internet and thump their chests over how great of a group they can shoot from X rifle with Y ammo "all day long."

 

[komifornian]

I only ever shoot groups if I'm doing load development or have changed something on the rifle and want to make sure accuracy has not been affected, I really don't see the point of them otherwise, I think hitting what you're aiming at is far more important. It's become a pet peeve of mine that people will brag about a 1/2 MOA group that is 4" off the mark of where they should have hit. Ridiculous. That being said, when doing groups I use 5 shots, however 3 shots to 5 shots doesn't seem to change the accuracy for me.

I thought I was the only one that had this "pet peeve!" I never understood why a small five shot group where all the shots missed was acceptable. Why not just dial the scope so that the group hits the target? Essentially all these folks are getting are five misses which happen to be in a group.

 

[bodywerks]

Groups for the sake of groups is Benchrest shooting. Most people tend to try to get their groups in the, uh, bullseye. If I'm looking to zero my rifle or do load development I still adjust as needed to get on the bull.
I do spend a lot of time at the range punching paper, but its all in an effort to improve basic shooting technique or gather data, so i try to get it on the bull every time.

 

[mwilkins]

With my Grendel I shoot 4 shot groups. Because that is all my AA mags will hold......

On another note, I just noticed my post count is only 1. Anyone else loose their post history?

 

[VKC]

I don't think there is a solid industry standard that is always adhered to by all companies. Some shoot 3-shot groups and cherry-pick the best one. Others do 5-shot groups. The best I've seen is the average of 5 five-shot groups.

There is also the question if the shooter can shoot well enough to maximize the rifle's potential.

Statistically speaking the more shots you take the larger the sample size, and usually the less likelihood for variation from the true average of results and the less standard deviation.

I personally prefer to gauge a rifle's accuracy by 10-shot group averages.

 

[Rapidrob]

A ten shot group after the bore has been fouled to remove any oil in the bore from the last cleaning.

 

[MarinePMI]

Five shot groups for accuracy, three shot groups for redoping...

 

[707FreedomFan]

2 shots of espresso, 3 shots on paper! Jk

I was shooting a killer group once and blew it on round 5, so I waited a few minutes and started again, stopped at round three and had something to make the egotistical raise an eyebrow.

I get group fever usually after a couple clean shots, so I stick to steel. I have a long ways to go...

 

[leadbullet]

as many as possible, if the group stays one hole I keep going till a flyer or the barrel is too hot to see the target.

 

[James n TN]

I've lived by this saying for many years. Three shots is the load five shots is the shooter.

You guys who believe in 5 shot groups for accuracy that's fine. I will load develope my three shot groups over two chronographs and once I find my load I'll go back and verify my results before I am comfortable enough to go shoot a match. One more thing some of the top benchrest shooters in the world only shoot three shot groups for accuracy loads.
Also we are shooting groups at 600 yards in the 1.5" range for five shots not a 12"x12"plate at 500-600 yards.
Each type of shooting has its own discipline and accuracy needs. Mine I have to have a rifle capable of shooting 1/4" on avg and less at 200 yards.

sent from my RAZR Maxx HD using Tapatalk 2

 

[predatornut]

The size of the group should relate to the type of rifle and the role it will play. It makes no sense to shoot five or ten round groups out of a pencil barreled mountain rifle when it will only be shot once or twice at a time in the field. If it is a competition rifle that will need to maintain poi through dozens of rounds then you really can't have too many rounds in the group. For a long range gun, I shoot5 round groups because when I take the time to drive somewhere and set up my targets I am not going to put 10 rounds down range and call it a day.

 

[rootbrain]

For semi's a 5 shot group (or more) will give you a better feel on accuracy for cold barrel vs. hot barrel.

With bolts, the time between shots is greater so it's not as big a deal.

Rootbrain

 

[praharin]

I've lived by this saying for many years. Three shots is the load five shots is the shooter.

You guys who believe in 5 shot groups for accuracy that's fine. I will load develope my three shot groups over two chronographs and once I find my load I'll go back and verify my results before I am comfortable enough to go shoot a match. One more thing some of the top benchrest shooters in the world only shoot three shot groups for accuracy loads.
Also we are shooting groups at 600 yards in the 1.5" range for five shots not a 12"x12"plate at 500-600 yards.
Each type of shooting has its own discipline and accuracy needs. Mine I have to have a rifle capable of shooting 1/4" on avg and less at 200 yards.

sent from my RAZR Maxx HD using Tapatalk 2

You're exactly right. The purpose for a 5 shot group is to test the entire system, not just one component, including the shooter. It's also more statistically significant, as stated above. I think that by the time one is among the "top benchrest shooters" in the world, a one shot group could be sufficient, as these people know anything that went wrong, if something went wrong.