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> Fliers are illusory
Fliers are illusory
@ 04:55 am (GMT) |
Scott StruifIn the below video, Bryan Litz explains how he recently came to conclusion that fliers should not be considered anomalous aberrations. He said his company was hired by the military to conduct barrel life testing on various barrels, which required shooting 1500 rounds of the same load through the same barrels in 5 or 10 shot groups. A pattern emerged in the accuracy data.At 15:30 in the video, he says that a barrel that averages 1 MOA will shoot groups ranging from .4 to 1.6 MOA, assuming a sample size of 100 shots, shot in 20 five-shot groups. https://youtu.be/Z0RC17Dbtws?si=4YMXu-lpRSTKMfa9 |
Replies
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@ 12:52 pm (GMT) |
Scott StruifRe: Fliers are illusoryThe reason I posted Litz’s observation here is, I’m trying to figure out a way to use his math to extrapolate what an average group might be be based on a smaller dataset.In other words, if I shoot 4 five-shot groups, none of which exceeds 1.6 MOA, is it reasonable to conclude the gun is averaging MOA? |
@ 06:29 pm (GMT) |
David LenziRe: Fliers are illusoryScott,Litz has already done that math for you ;-). His second book has a table of statistical/mathematical equivalencies. The 5 shot group average will be approximately 1.28 times larger than a rifle's three shot group average. A 10 shot group aberage will be approximately 1.58 times larger a rifle's three shot group average. A 20 shot group will be approximately 1.85 times larger than a rifle's three shot group average. A 30 shot group will be approximately 1.99 times larger than a rifle's three shot group average. A 20 shot group will be ~ 1.45 times larger than a rifles's five shot group average. A 30 shot group will be ~ 1.56 times larger than a rifle's five shot group average. That all begs the question of how robust your sample needs to be to establish a true average. |
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@ 06:38 pm (GMT) |
David LenziRe: Fliers are illusoryI'm not sure if my proof reading or my typing is worse...One thing I don't see people do all that often... put up a target backer that has a grid reference on it. Mount your individual targets on top of this in the same place as you shoot your individual groups. The target backer will have an aggregate group on it once you have completed firing your 3 or 5 shot groups... and it will tell you a lot about your consistency on the gun as you compare the aggregate and the individual targets. You can also do this via computer software now... or by measuring from your point of aim and assigning coordinate to each shot in Excel (I've done this... it's tedious). You can get things like mean radius and standard deviation as well as ES for groups this way. Which is good for larger groups because, as Litz points out, ES throws out the information from every data point but your two worst. An alternative to the above was something I saw posted years ago and attributed to none other than White Feather himself. Because the cold bore shot is the most important, log/record (even save the target) your cold bore shot every range session. Aggregate your cold bore shots. Again, it will tell you a lot about your consistency on the gun. |
@ 09:04 am (GMT) |
Nathan FosterRe: Fliers are illusoryHi Scott, try to strip things back to the basics rather than adding theory. The internet is very useful and people like Brian Litz have a great deal of experience and knowledge but too much information, including my own, can become disempowering if the result is inaction. Too much time on the computer will also ruin your eyesight and therefore your ability to shoot or locate game in low light. Our eyes are not designed to stare at a close fixed point for such long periods of time. Nor is this any good for our bodies.Your question infers that you want to use statistics to obtain confidence in your rifle. The following answer is grossly over simplified: If you have a factory hunting rifle, there is only so much control you have over variables. You cannot for example determine whether the receiver is square or whether chamber is concentric or how the barrel was finished. But there is much you can do to reduce variables including the main factor which modern shooting authorities completely ignore - technique. Basic checks include observing and testing the fit of the receiver within the stock and visually observing the barrel. You don't have to have a bore scope for this, one can get by via observations of the muzzle as explained in the book series. With these factors squared away as best you can as an end user, you can move on to reloading, working up basic loads. Once you have your loads, set about range testing putting your focus into technique, holding the rifle like a tool as opposed to holding it like a fashion accessory. All of this you already know and is a key factor of accuracy. While test shooting, take your time to get to know the individual bore - how it looks as it fouls and the results thereof as you progress through group tests. If the rifle produces zero copper fouling, then you will likely have to back off cleaning altogether in the hope that the bore obtains and then maintains even resistance within. A dull and almost transparent bronze rouge effect is perhaps optimal while bright orange generally indicates a potential fouling problem which will invariably show up in the groups. If fouling is heavy, follow the steps I have outlined in the book series (see also Rem 700 trouble shooting / stubborn fouling video under video learning tab). Fast forwarding and again obviously over simplified - Observe which test group is best and then set about retesting. The second round of testing will provide initial confirmation. The cold bore shot should be recorded from now on because it is the one that counts if you intend to use the rifle for what it was designed for (i.e. a killing tool). If all is well, you might want to move onto scope tracking (if it is a long range rig). This will provide you with two more groups if testing elevation only. Once this has been done, move from the bench to your field position / field rest. This round of testing provides further confirmation. If there are fliers present, you will need to determine whether it is a problem with your load or your technique. You'll work it out one way or another. By the time you are done, you will have your field zero sorted and will be confident in the rifle, the cope, your loads and yourself. Either you have confidence in the rifle or you don't. You cannot obtain final confidence in this matter from the internet. I have of course neglected to discuss factors such as ES. More on this and other subjects can be found in the books. I would agree, fliers don't happen without cause. On the other hand, I do not agree with current opinions on the cause of fliers. I have also been conducting my own tests on barrels this year. It is not a military contract but is instead voluntary work for manufacturers in the hope that results will benefit end users. |
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@ 09:18 am (GMT) |
Scott StruifRe: Fliers are illusoryThanks David. In the video, Litz says his math is based on the statistics of large sample sizes he observed recently. The table in the book may be outdated. According to his recent observations, his .6 MOA gun’s largest group would be .96. He specifically said you can’t throw out fliers. In other words, if he shoots a 5 shot group, 4 of which are in 1 ragged hole, and the 5th is .96 off, he can’t say he pulled it and throw it out. Instead, his math tells him his gun is averaging .6, not the .1 of the ragged hole. By the same logic, if I shoot a 1.6 MOA group, I can confidently declare my gun to be a 1 MOA rifle, and leave the range in a good mood, instead of pissed off like I usually do. |
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@ 10:12 am (GMT) |
Scott StruifRe: Fliers are illusoryTouché, Nathan. It’s time to quit thinking and start plinking! |
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@ 12:40 pm (GMT) |
David LenziRe: Fliers are illusoryScott,I think a big part of the issue is people talk about flyers in a way that excuses the rifle as a part of the system... the "when I do my part" accuracy claims are automatically attributing normal dispersion/performance to shooter error to save placing blame on the rifle. Nathan covers this well I think - you gain experience, you are attentive to the rifle and the shot. Was there a sudden gust of wind? Did the recoil indicate a under/over charge? If the shot looked good and felt good, calling it a "flyer" and placing the blame on the shooter is dubious... some people just have a hard time accepting that their $300 "just as good as" rifle isn't, even when they do their part. As Nathan says above, and was noted on a different forum recently, the numbers can be interesting, but there's no substitute for shooting the gun. For my part, I use them to inform my performance standards and expectations - which really just support what Nathan says: if you want to shoot long, your 3-shot groups should be (well) under a half inch at 100 yds. The other big issues with discussion of flyers and precision generally is recoil management... or the lack thereof by the shooter. Candidly, the more I read Litz, the more I appreciate Mr. Foster... I've reread all Nathan's stuff over the last month or so and it's really tremendous just how much of what Litz publishes simply adds empirical support to what's already in the Practical Guide series. Dave |
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@ 08:24 am (GMT) |
Nathan FosterRe: Fliers are illusoryThanks David, that was very kind of you to say.Hope the rifle performs well for you Scott. |
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