Bullet goes to sleep mode

[Raythemanroe]

I wonder how many times a engineer has been told that can't be built by some educator?


Ray

 

[Raythemanroe]

Question, Was a boat tail a design element for down range or in the muzzle performance? Will a high BC boat tailed bullet only out perform if they are wind and conditions? If boat tailed high BC bullets do out perform at distance regardless of wind, does that mean they will out perform at point blank ranges?


Ray

 

[MattPeetz]

If a well seasoned trusted shooter says he has experienced linear dispersion before, I wouldn't assume that he means all of his guns currently show this.. I would first ask how common and how likely are you to have a gun that performs that way.. I would not suggest for them to show me now or it is debunked, nor would I rest all my knowledge on someone I have never met.. I wonder If Bryan broadcasts how many failed experiments he has to one successful one.. Do you know if any of his efforts was to prove linear dispersion correct or all efforts were to prove it wrong, this is a very important question..

Ray

Make sure to buy his book that is coming out.
I am not going to speak for Bryan but his testing clearly shows linear dispersion happens.
Again, i am not going to speak for Bryan but he clearly states that if this non linear dispersion is true, he wants to understand it.
You can not understand a bullets flight by shooting at one target and get a group, then shooting at another target to get a group and say you know how a bullet flies.

 

[Grimstod]

If a well seasoned trusted shooter says he has experienced linear dispersion before, I wouldn't assume that he means all of his guns currently show this.. I would first ask how common and how likely are you to have a gun that performs that way.. I would not suggest for them to show me now or it is debunked, nor would I rest all my knowledge on someone I have never met.. I wonder If Bryan broadcasts how many failed experiments he has to one successful one.. Do you know if any of his efforts was to prove linear dispersion correct or all efforts were to prove it wrong, this is a very important question..

Ray

Bryan in his own words took this project on because he WANTED to proove that it existed. Not because he wanted to disproove it.

The fact is no specimen has been recorded to exist. Your searching for big foot.
Hope i did not open a can of big foot supporters

 

[3Ackleys]

Litz works on the design of Berger bullets and says there has been no proof of them going to sleep.
If Berger could say in their ads that their bullets will shoot better at long range than close range they would be doing it.

There is a gun builder here that tells all his customers not to worry about how their $4000 gun shoots at 100 yds because the bullets go to sleep.
The 2 i shot were 1.25" and 1.5" at 100 yds and 10"+ at 600 yds.
I told the owners to dip their bullets in Nyquil

 

[BoydAllen]

Fellows,
I may have some relevant information. Years, or should I say decades ago, when C E Harris was writing for The American Rifleman, he published an article about a test that he did comparing the accuracy of the .308 with that of the .30-06. He used 10 and 12 inch twist barrels, that were chambered in first one caliber and then the other and the same bullets for both. What he found was that the tighter twist did better a long range, and the slower at 100 yards, and since virtually all of the writers had done their testing at 100 yards, and the standard twist for the .30-06 was 10 and for the .308 it was 12, that the difference in reported accuracy was very likely because of that difference rather than case design.

Another related piece of information goes back to when Ruger changed the twist on their 7mm magnums to a faster one. (I forget the numbers.) The reason given was that the new twist was more accurate at long range with heavier bullets, not that they had key holed with the old twist, but that the faster twist was more accurate.

I realize that neither example meets the standard of scientific proof, but they do speak to the issue at hand. We all know that short range benchrest has historically been shot with twists that are on the slow side (for the bullet lengths used), because that is what has given the best results, and that long range shooters have not followed that path, relative to their longer bullets. They seem to be working with a greater safety margin on stability, because that is what has worked at long range. Perhaps that is the answer to the question. Whether this is about what is referred to as bullets going to sleep is a related question, but there seems to be data that indicates that more marginal twist rates do relatively better at 100 yards.

 

[mike a]

Fellows,
I may have some relevant information. Years, or should I say decades ago, when C E Harris was writing for The American Rifleman, he published an article about a test that he did comparing the accuracy of the .308 with that of the .30-06. He used 10 and 12 inch twist barrels, that were chambered in first one caliber and then the other and the same bullets for both. What he found was that the tighter twist did better a long range, and the slower at 100 yards, and since virtually all of the writers had done their testing at 100 yards, and the standard twist for the .30-06 was 10 and for the .308 it was 12, that the difference in reported accuracy was very likely because of that difference rather than case design.

Another related piece of information goes back to when Ruger changed the twist on their 7mm magnums to a faster one. (I forget the numbers.) The reason given was that the new twist was more accurate at long range with heavier bullets, not that they had key holed with the old twist, but that the faster twist was more accurate.

I realize that neither example meets the standard of scientific proof, but they do speak to the issue at hand. We all know that short range benchrest has historically been shot with twists that are on the slow side (for the bullet lengths used), because that is what has given the best results, and that long range shooters have not followed that path, relative to their longer bullets. They seem to be working with a greater safety margin on stability, because that is what has worked at long range. Perhaps that is the answer to the question. Whether this is about what is referred to as bullets going to sleep is a related question, but there seems to be data that indicates that more marginal twist rates do relatively better at 100 yards.

Decades ago I had a copy of the American Rifleman. I thought it was by Jack O'Conner. Sure would like to find it again. Great book.

 

[Grimstod]

Question, Was a boat tail a design element for down range or in the muzzle performance? Will a high BC boat tailed bullet only out perform if they are wind and conditions? If boat tailed high BC bullets do out perform at distance regardless of wind, does that mean they will out perform at point blank ranges?


Ray

It actually isnt the design of the bullet. Its the twist rate that causes flat based bullet to fly best at those shorter ranges. There is a detailed chapter in Bryans first book on this very topic. Highly recomend reading it. Ray i recomend getting the book and reading that. I have let a friend barrow it for now so i cant rememberoff the top of my head which chapter it was exactly.

 

[Raythemanroe]

Bryan in his own words took this project on because he WANTED to proove that it existed. Not because he wanted to disproove it.

The fact is no specimen has been recorded to exist. Your searching for big foot.
Hope i did not open a can of big foot supporters

You keep repeating Bryan says so so it is law

Guys, buy a different book.. Maybe expand to some new possibilities

"we haven't observed non-linear dispersion in any of the testing that we've done, but we still can't claim with certainty that it doesn't happen" Bryan Litz

Ray

 

[chkunz]

You keep repeating Bryan says so so it is law

Ray

The reason folks keep quoting Litz as well as others (Harrison, Davis, Audettee, More, etc.) is that they have published data with detailed technical explanations of how the data was acquired. Others say "I have seen it" or have a friend that "has seen it" and this is not convincing as compared with the published date for these folks.

 

[Raythemanroe]

The reason folks keep quoting Litz as well as others (Harrison, Davis, Audettee, More, etc.) is that they have published data with detailed technical explanations of how the data was acquired. Others say "I have seen it" or have a friend that "has seen it" and this is not convincing as compared with the published date for these folks.

If it is in print it is law? what about if it is on the internet?

Ray

 

[chkunz]

If it is in print it is law? what about if it is on the internet?

Ray

No, if it is in print it is not law. You have to consider the source, reputation, the data acquisition and analysis methods and then you decide. If something appears to be contrary to the laws of physics and statistical analysis then it gets great scrutiny and very well it should. But there are new discoveries from time to time and we eventually vet them with technical analysis and if they are valid we accept them as fact.

 

[mike a]

It's not a great rifle but it holds 1/2 moa. Except at 100 yards. Really! I get 3/4 " at 100 and 1" at 200 and 1/2 moa from there to 500. Not just a few groups but many. Is there any real tested evidence for this. Even though I see with my own eyes it's hard to except.

Hey guys, OP here again. So I've done some more shootin sense I started this monster thread. So it's a .243 10twist, pushing a seirra #1515 at about 3300. I took some advise and super tweaked my paralex and made my aim point much smaller. Instead of .75 moa at 100 I got .66 agg of three 3 shot groups. Thing is my 200 was around .72. So no real evidence there. Hell, I don't shoot 100 much and only did cause I wanted a 1/2 group for my wallet. Soooo, what if I change bullets? Sort of defeats my particular phenomenon but I'm gonna try it. I have a load for the sierra #1510. ie boatail to flat base. We'll see what it does at 1 and 200. Watch me get 1/2" at 100 and 1" at 200.(bang head on shooting bench) But that's it. My Howa baby has 800 rounds though it and I'd like it to last awhile longer. If it doesn't work then I'll just never shoot 100 again for the rest of life!!! Cheers Mike A

 

[Webster]

I was at Brian Litz’s seminar this February up in Tustin, MI and one of the subject of his presentation was this “phenomenon”.

Bryan Litz's post on YOUTUBE. Does a bullet go to sleep. What am I missing?

An Army Report on things like yaw.
http://www.arl.army.mil/arlreports/2010/ARL-TR-5182.pdf
Looks like the yaw decreases with time in flight.

 

[Joe Salt]

I guess you would have to have a perfectly aligned range to do the test, so that leaves me out. But I know my 1000 yard load will not shoot for crap at 600!
So back to the drawing board. It's still about Barrels and Bullets.

Joe Salt

 

[Webster]

I guess you would have to have a perfectly aligned range to do the test, so that leaves me out. But I know my 1000 yard load will not shoot for crap at 600!
So back to the drawing board. It's still about Barrels and Bullets.

Joe Salt

The bottom line is always shoot the rifle and find out what works.

 

[Homerange]

Fellows,
I may have some relevant information......

Another related piece of information goes back to when Ruger changed the twist on their 7mm magnums to a faster one. (I forget the numbers.) The reason given was that the new twist was more accurate at long range with heavier bullets, not that they had key holed with the old twist, but that the faster twist was more accurate.

244 Rem, 6mm Rem another example of a manufacturer realising the error of their ways.

 

[jlow]

Fellows,
I may have some relevant information. Years, or should I say decades ago, when C E Harris was writing for The American Rifleman, he published an article about a test that he did comparing the accuracy of the .308 with that of the .30-06. He used 10 and 12 inch twist barrels, that were chambered in first one caliber and then the other and the same bullets for both. What he found was that the tighter twist did better a long range, and the slower at 100 yards, and since virtually all of the writers had done their testing at 100 yards, and the standard twist for the .30-06 was 10 and for the .308 it was 12, that the difference in reported accuracy was very likely because of that difference rather than case design.

Another related piece of information goes back to when Ruger changed the twist on their 7mm magnums to a faster one. (I forget the numbers.) The reason given was that the new twist was more accurate at long range with heavier bullets, not that they had key holed with the old twist, but that the faster twist was more accurate.

I realize that neither example meets the standard of scientific proof, but they do speak to the issue at hand. We all know that short range benchrest has historically been shot with twists that are on the slow side (for the bullet lengths used), because that is what has given the best results, and that long range shooters have not followed that path, relative to their longer bullets. They seem to be working with a greater safety margin on stability, because that is what has worked at long range. Perhaps that is the answer to the question. Whether this is about what is referred to as bullets going to sleep is a related question, but there seems to be data that indicates that more marginal twist rates do relatively better at 100 yards.

If I remember correctly, Brian testing a range of twist but was unsuccessful in showing this phenomenon in a reproducible fashion. He tried many calibers and a huge range of powder charge, etc but in the end, despite what looks like an effort to prove that it exist, he was unable to come up with a single instance. This is why he has an open invitation to anyone who thinks they can do it reproducibly i.e. what he wants is at least ONE instance where he can show this. The rationale of course is if it can be done even with a single rifle/load, he can take it apart it to find out the reason why it happens.

 

[BoydAllen]

Fortunately this is not a matter of great importance to the kind of shooting that I do. Harris wrote that he did the test that I described. I reported the gist of his results. The same is true for the change that Ruger made. Since I did not participate in either situation, I cannot speak to the quality of the work that led them to their conclusions.

 

[Joe Salt]

Don't forget Weatherby they were using a 12 twist in the 300 until they figured out a 10 twist was the way to go with bigger bullets. Oh if some of you skeptics think a bullet doesn't wobble coming out of the barrel, watch Lee Ermey's show on the outdoor Chanel. They do a lot of slow motion pic's.

Joe Salt