Bullet goes to sleep mode
- Thread starter mike a
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Ned Ludd
Silver $$ Contributor
That is not what Damon or others are saying at all. What we're saying is that dispersion only increases with distance, not decreases. If you believe otherwise, it shouldn't be difficult to provide definitive evidence of said behavior. The overwhelming preponderance of scientific data is not in favor of decreased dispersion at longer distance.
Raythemanroe
Bullet Whisperer
It's what Litz is saying, so now you fellas just pick and choose what rules you go by right? Lol
Ray
Alex Wheeler
Site $$ Sponsor
There are two scenarios here. One, a bullet stabilizes down range. I am not sure if that happens or not. I have no opinion. The other is positive compensation. This is a fact. And without doubt you can see smaller groups (moa wise) down range due to this. Goes back to the enfield rifles even.
Yep
I don't believe they deviate from their path at all. That yaw is less than half a bullet diameter around the bullets CG. By 100 yrd it is for all intents and purposes gone. If it wasn't you would see it on the target.
Except when bullets leave the muzzle axis on its upswing that compensates for slower one's greater drop at target range.
Not at all. Where you call the shot is where the rifle's grouping area will center. If the rifle tests 1 MOA at range and you call the shot at the edge of your 1/2 MOA holding area, the bullet will strike within 1/2 MOA from that point; in any direction. If your body doesn't hold the rifle exactly the same, how much it torques from recoil while the bullet goes through the barrel can bullets to strike further away. We call the shot after hearing the shot fired. The muzzle actually points to somewhere else than where we think it does.
Which is why someone shooting prone calling all shots inside a 1/2 MOA circle shooting a 1 MOA load has his shots strike inside a 2 MOA circle; if all goes well. A 2.5 MOA circle is more likely as nobody dopes the wind smaller than 1/2 MOA units all the time.
Ned Ludd
Silver $$ Contributor
LOL. All I'll say is simply provide the evidence Bryan Litz asked for, and you get the prize. Otherwise, the bullets going to sleep idea and groups getting smaller with distance will remain an internet myth. This whole discussion is even less useful than those concerning current political topics.
Alex Wheeler
Site $$ Sponsor
What prize? And why? There are plenty of long range shooters that are aware of this. First, if you tune at 100 you will never see it. If .5 moa at 1k is good enough you may never see it. Litz is not a Br shooter so I am not surprised he has not seen it. Ask a good 1k br shooter and see what they say. Its not even debated in that circle.
http://www.geoffrey-kolbe.com/articles/rimfire_accuracy/tuning_a_barrel.htm
Google positive compensation
Ned Ludd
Silver $$ Contributor
I know what it is. As I said, if compensation is the answer that explains an decrease in angular dispersion over distance, it should be quite easy to demonstrate, or merely reproduce the data if it has already been conclusively demonstrated as you're implying. The "prize" mentioned was an offer Bryan made here and elsewhere some time ago to anyone that could do so. In fact, it's been so long I can't even remember what the "prize" actually was. I don't know if the offer is even still good, but if it has ever been claimed, I haven't heard about it. If not, it ought to be a simple exercise for any BR shooter that knows about compensation to demonstrate an decrease in angular dispersion over distance. I'll be among the first to offer my congratulations to anyone that does so.
Ned Ludd
Silver $$ Contributor
From my understanding of it, your results are well-supported by the compensation theory. However, the question over which this thread arose quite some time ago had to do with the idea of bullets going to sleep at some point after exit from the muzzle and how that might explain the notion that smaller angular dispersion could be obtained at a longer distance than at a shorter distance (i.e. smaller groups at longer distance). There have been several other threads over the years in which the same topic was discussed, and they probably are still around. If memory serves me, it was in one of those that Bryan made an offer of some kind of prize to anyone that could provide solid evidence of angular dispersion getting smaller as distance increased. To be honest, it's been a while and I don't remember the exact details of it.
The compensation work I am familiar with has strictly focused on grouping at a specific distance and how muzzle angle at bullet exit from the bore can effectively compensate for minor velocity variance to produce smaller vertical dispersion than might be expected otherwise. It is in agreement with what you showed above. However, IMO - the evidence that has been lacking and probably why this thread is even still going on after two years is that no one seems to monitor to what the bullets are doing at distances intermediate to the target. It's one thing to show cartoons of parabolas to illustrate that the intermediate distance vertical dispersion is much larger when compensation is maximized at some longer distance (i.e. the slower bullet has the higher arc). However, providing direct [measured] evidence with the exact same bullets that the intermediate distance angular dispersion of those bullets while on their way to the longer distance target is actually larger than when they arrive at the final target is probably not such a simple thing to accomplish in a definitive manner.
For example, shooting separate groups with the same setup/load at different differences will always leave room for doubt. The experiment really needs to be carried out so as to generate two groups at different distances with the exact same bullets. I've seen a number of posts in which people were shooting through paper to generate two groups at different distances with the same bullets. This also is unsatisfactory because it is impossible to ever state with certainty that passing through a solid object, even one as thin as Bible paper, didn't have sat least some effect on the trajectory of the bullet. However, I would allow that it is most likely that contact with the paper would increase dispersion rather than somehow decrease it after the bullets passed through. Even so, the use of paper in between the intermediate and final distances is problematic. One approach might be to use high speed cameras located above and to the side of the bullets' paths at some intermediate distance, with some type of calibrated measurement device visible in the field of view such that dispersion could be directly measured in individual frames. Not many have access to that type of equipment, which likely explains why it hasn't been done, at least AFAIK.
I think at least some proportion of the claims posted on the internet about shooting two inch groups at 200 yd and one inch groups at 300 yd have to be attributed to a variety of factors that don't constitute any kind of reproducible mechanism. For others, it may well be that compensation provides the explanation for decreasing angular dispersion over distance. Trajectory calculations certainly suggest that it should. However, there are certainly examples of calculations that had been accepted for some time that were later proven to be in error for reasons that weren't apparent at the time they were considered accepted. In my estimation, providing direct measurable evidence of decreasing angular dispersion over distance is not such an easy thing to accomplish. Then again, it might simply be that all it requires is someone much smarter or more clever than myself. In that case, maybe it won't be too hard to provide the direct evidence. If so, I'll be among the first to offer my congratulations as I said. Just out of curiosity, with the loads you showed above, have you ever shot groups at some intermediate distance? It would be expected that under conditions of compensation the grouping would show substantially more angular dispersion in the vertical at the shorter distance.
The compensation work I am familiar with has strictly focused on grouping at a specific distance and how muzzle angle at bullet exit from the bore can effectively compensate for minor velocity variance to produce smaller vertical dispersion than might be expected otherwise. It is in agreement with what you showed above. However, IMO - the evidence that has been lacking and probably why this thread is even still going on after two years is that no one seems to monitor to what the bullets are doing at distances intermediate to the target. It's one thing to show cartoons of parabolas to illustrate that the intermediate distance vertical dispersion is much larger when compensation is maximized at some longer distance (i.e. the slower bullet has the higher arc). However, providing direct [measured] evidence with the exact same bullets that the intermediate distance angular dispersion of those bullets while on their way to the longer distance target is actually larger than when they arrive at the final target is probably not such a simple thing to accomplish in a definitive manner.
For example, shooting separate groups with the same setup/load at different differences will always leave room for doubt. The experiment really needs to be carried out so as to generate two groups at different distances with the exact same bullets. I've seen a number of posts in which people were shooting through paper to generate two groups at different distances with the same bullets. This also is unsatisfactory because it is impossible to ever state with certainty that passing through a solid object, even one as thin as Bible paper, didn't have sat least some effect on the trajectory of the bullet. However, I would allow that it is most likely that contact with the paper would increase dispersion rather than somehow decrease it after the bullets passed through. Even so, the use of paper in between the intermediate and final distances is problematic. One approach might be to use high speed cameras located above and to the side of the bullets' paths at some intermediate distance, with some type of calibrated measurement device visible in the field of view such that dispersion could be directly measured in individual frames. Not many have access to that type of equipment, which likely explains why it hasn't been done, at least AFAIK.
I think at least some proportion of the claims posted on the internet about shooting two inch groups at 200 yd and one inch groups at 300 yd have to be attributed to a variety of factors that don't constitute any kind of reproducible mechanism. For others, it may well be that compensation provides the explanation for decreasing angular dispersion over distance. Trajectory calculations certainly suggest that it should. However, there are certainly examples of calculations that had been accepted for some time that were later proven to be in error for reasons that weren't apparent at the time they were considered accepted. In my estimation, providing direct measurable evidence of decreasing angular dispersion over distance is not such an easy thing to accomplish. Then again, it might simply be that all it requires is someone much smarter or more clever than myself. In that case, maybe it won't be too hard to provide the direct evidence. If so, I'll be among the first to offer my congratulations as I said. Just out of curiosity, with the loads you showed above, have you ever shot groups at some intermediate distance? It would be expected that under conditions of compensation the grouping would show substantially more angular dispersion in the vertical at the shorter distance.
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dcali
Bullet Maker
As with eveyrthing Kolbe authors, that's a great article. The most important and least understood part:
"The influential American rimfire gunsmith Bill Calfee, in an article written for Precision Shooting Magazine ("I'm Feeling Those Good Vibrations AGAIN!" Vol. 52, No. 11, March 2005) presented a rather novel view on how barrels vibrate, and also expressed his belief that for best accuracy, barrels should be tuned so that the muzzle is "stopped" and there is no change in muzzle angle, or position, as the bullet is launched. It should be noted that Calfee's theories have absolutely no basis in fact and are mathematically untenable. But that does not stop it being the most quoted work in the popular press on barrel vibrations and the tuning of barrels."
That only happens when the spread in muzzle velocity is zero as well as the barrel time it took for the bullet to exit at that point. To date, I don't think anyone has worked up a load that does that. It is contrary to what Al Harral and Geoffery Kolbe have proved.
It's akin to those believing the barrel is absolutely still until the bullet leaves. Browning tried explaining their BOSS worked by tuning barrel whip so bullets left when the barrel was straight out. They never considered that's the place where its muzzle whip changes in angle at the greatest rate; top and bottom of that vertical whip cycle has the least change rate.
I think Brian Litz' challenge will be limited to 300 yards; hard to prove all the time. But benchrest rifles often have tuners and their owners see the results. So does the rimfire crowd. As Kolbe's page on his tests with rimfire ammo shows.
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That what a
Tuner does
Helps you find a vibration where the barrel stops moveing
You don't see a rim fire win without one . Gun vibration sure change bullet flight Paper test a tune and you will see the aproxment area that it happens . A vertical angle up or down from the point of aim Show a difference in paper holes shapes. The smaller the hole tells if your bullet is asleep or not . Larry
Tuner does
Helps you find a vibration where the barrel stops moveing
You don't see a rim fire win without one . Gun vibration sure change bullet flight Paper test a tune and you will see the aproxment area that it happens . A vertical angle up or down from the point of aim Show a difference in paper holes shapes. The smaller the hole tells if your bullet is asleep or not . Larry
dcali
Bullet Maker
There were more than a couple articles about vibrations in PS that were completely wrong. This was just one of them. Everyone wants it to be simple and it's just not.
dcali
Bullet Maker
Yaw creates lift which is why it *does* change the path. That's how epicyclic swerve happens. It's just not as big as people seem to think.
Then there's the Flat Earth Society whose members are convinced the earth is flat.
All the 100 yard rimfire records set prior to the early 1980's still stand. No tuners used back then. But tuning's not the reason; ammo was more accurate back then.
I'd guess that no more than 20% of rimfire match winning barrels are "tuned." RWS and Eley don't use tuners on their test barrels.
This match and range best plus near record breaking score with my Anschutz rimfire 22 didn't have a tuner. X ring's .39", all groups are MOA or under. Some holes had 5 people in the stat office check them as the scoring plug was in them. Shot in 2006(?) with a 1981 lot of Eley Tenex. Two Xes in the shoot off then a 10 out right from a wind gust as it fired. Senior record was 400-40X +5.
All the 100 yard rimfire records set prior to the early 1980's still stand. No tuners used back then. But tuning's not the reason; ammo was more accurate back then.
I'd guess that no more than 20% of rimfire match winning barrels are "tuned." RWS and Eley don't use tuners on their test barrels.
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Are you saying slightly out of round bullet holes in target paper prove bullets were not stabilized at that point in their trajector?
Wouldn't bullets have to always enter target paper at a 90 degree angle to their surface to make perfectly round bullet diameter holes?
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Yes. Some even are smaller then the bullet .
Larry
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