- Oct 30, 2004
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let's say you get 1.2" at 100 is it possible (has anyone seen this?) to get 1.7" at 200 and let's say 2.5" at 300----just an example.
Better MOA at longer ranges??????
- Thread starter FOTIS
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- Oct 30, 2004
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yup inches I changed it thanks
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no not at all!!!
DrMike
Ballistician
- Nov 8, 2006
- 37,417
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I have a 7 RM that shoots 1.5 inches at 100 yards and 1.5 inches at 200 yards. That is with the 175 grain PT. First time I'd ever witnessed this. It is a consistent observation, however.
TackDriver284
Handloader
- Feb 13, 2016
- 2,564
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I have seen bullets " go to sleep" at ranges over 200 yards. Sometimes bullets tend to stabilize itself a lot better the further it travels. I also believe that this does happen and I suspect that, nothing being perfect, the gas pressure at exit is not perfectly symmetrical on the base of the bullet kicking it slightly into a wobble which goes away somewhere down range as the bullet stabilizes. Normally happens with long bullets.
I have a couple of rifles that will hold less than MOA all the way out to 600 yards. The 300 for example will shoot 1/2 " at !00 and last week I had one group under 2 inches, and the next at 1.1 at 300yards. Today the Mashburn put 6 shots in at 2.14 and 5 of those were in at 1.48. These groups were both at 300. Last month the Mashburn did 2.89 at 425, so from my experience the answer is yes. I really don't shoot much at 100 yards anymore, mostly 300. In fact when I read your post I looked for a 100 yard target from the Mashburn and couldn't find one. Is this what you were looking for?????
I am admittedly ignorant, and am asking, cause I don't know. I think I remember reading that Bryan Litz will pay to see a rifle that shrinks group size at further ranges. I understand it to be ballistically impossible, per his.theories. like, Shoot a bullet through one target at 100 and pass through to a target at 200, ballistics say it isn't going to shrink the group size.
Not to say you all are not seeing smaller groups, but I understand that group size shrinking is alleged more to do with the shooter and circumstances. easier to shoot small miss small at 200 over a closer target at 100.
If you know, how does it do that ballistically? I have never heard a scientific reason, other than the "going to sleep" but what shape trajectory is the bullet traveling? Is it like a banana between muzzle and 200, so that the group is open at 100, but then before 200 the bullet goes in a straight line? thats what I am having a hard time understanding.
I believe the targets show the phenomenon, but I cant see how a set of bullets would take a curvy path like that close in, but then come together later and then be a tighter group at further distance.
No one of which I am aware has given a tested scientific method to explain it, I certainly don't know...
Is there any information on it?
I have only heard the argument it can't happen. Curious what you all know about it.
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Not to say you all are not seeing smaller groups, but I understand that group size shrinking is alleged more to do with the shooter and circumstances. easier to shoot small miss small at 200 over a closer target at 100.
If you know, how does it do that ballistically? I have never heard a scientific reason, other than the "going to sleep" but what shape trajectory is the bullet traveling? Is it like a banana between muzzle and 200, so that the group is open at 100, but then before 200 the bullet goes in a straight line? thats what I am having a hard time understanding.
I believe the targets show the phenomenon, but I cant see how a set of bullets would take a curvy path like that close in, but then come together later and then be a tighter group at further distance.
No one of which I am aware has given a tested scientific method to explain it, I certainly don't know...
Is there any information on it?
I have only heard the argument it can't happen. Curious what you all know about it.
Sent from my SM-G920V using Tapatalk
HAWKEYESATX
Handloader
- Aug 15, 2016
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The science behind the phenomenon is as such:
The bullet, upon exiting the barrel, is over rotating. So, if there are any imperfections on the outside of the bullet, or internally, become more apparent within the first 100 yds.
Now, as the distance gets longer, air resistance become greater, along with gravity pull, and the bullet stops rotating as much, and it can find its "sweet spot" and rotates perfectly for its sectional density and ballistic coefficient, and becomes more accurate.
Now, other factors to consider, are barrel twist rate compared to bullet weight can
effect accuracy within the first 100 yds.
Choosing the right bullet for the rate of twist can be a great benefactor to long range accuracy.
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The bullet, upon exiting the barrel, is over rotating. So, if there are any imperfections on the outside of the bullet, or internally, become more apparent within the first 100 yds.
Now, as the distance gets longer, air resistance become greater, along with gravity pull, and the bullet stops rotating as much, and it can find its "sweet spot" and rotates perfectly for its sectional density and ballistic coefficient, and becomes more accurate.
Now, other factors to consider, are barrel twist rate compared to bullet weight can
effect accuracy within the first 100 yds.
Choosing the right bullet for the rate of twist can be a great benefactor to long range accuracy.
Sent from my LG-TP450 using Tapatalk
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- Oct 30, 2004
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Got it thaNKS
Cleveland48
Handloader
- Jul 28, 2015
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I have not witnessed this, but I’ve heard and read about it a lot.
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Have you found any research? I am genuinely curious. Again, using the best modeling, Litz said it isn't the pitch and yaw of the nose, or epicyclic swerve, as the nose of the bullet settled into a right spin.
And, if it happens at 600 and 1000, the bullet has already "gone to sleep" by 600, I presume.
Genuinely curious about the phenomenon. I like to understand, sometimes, your experience knows more than science, even if you can't "explain" how it is happening.
Thanks for the responses.
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And, if it happens at 600 and 1000, the bullet has already "gone to sleep" by 600, I presume.
Genuinely curious about the phenomenon. I like to understand, sometimes, your experience knows more than science, even if you can't "explain" how it is happening.
Thanks for the responses.
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Fotis;
Sorry for the temp derail.
I'm intrigued.
I wonder if there is any correlation between the slowing of rotation and bullet drop over long distances. As I was led to understand it the rotation degrades significantly slower than bullet drop.
Using a kids top as an example of starting slightly wobbly then stabilizing up it seems the example one of the other posts made does seem to make sense.
Guess it's another of those things that make you go hmmmmm.
Sorry for the temp derail.
I'm intrigued.
I wonder if there is any correlation between the slowing of rotation and bullet drop over long distances. As I was led to understand it the rotation degrades significantly slower than bullet drop.
Using a kids top as an example of starting slightly wobbly then stabilizing up it seems the example one of the other posts made does seem to make sense.
Guess it's another of those things that make you go hmmmmm.
There is also the question of whether group size containing any number of shots quantifiable in real-world conditions represents a statistically viable sample given the number of potential variables.
Even the fastest loads with the highest BC will be affected significantly over 300 or more yards of flight by the slightest wind. Now, to fire a group representing a significant sample in "same" conditions at range becomes a very difficult thing to do. Unless anybody on here has an underground climate controlled shoot tunnel, I think any evidence is anecdotal at best.
I can speak in terms of 10 and 20 shot strings in high power. I have witnessed a load outgroup it's predicted MOA at range based on previous firing at shorter ranges. I have also witnessed the groups at range spread significantly based on an unnoticeable condition change. Same load, same rifle, same day. Random.
Even the fastest loads with the highest BC will be affected significantly over 300 or more yards of flight by the slightest wind. Now, to fire a group representing a significant sample in "same" conditions at range becomes a very difficult thing to do. Unless anybody on here has an underground climate controlled shoot tunnel, I think any evidence is anecdotal at best.
I can speak in terms of 10 and 20 shot strings in high power. I have witnessed a load outgroup it's predicted MOA at range based on previous firing at shorter ranges. I have also witnessed the groups at range spread significantly based on an unnoticeable condition change. Same load, same rifle, same day. Random.
Dr. Vette
Handloader
- Apr 16, 2012
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Litz did some testing a couple of years ago in an effort to figure this out.
In the end, zero objective evidence that bullets "go to sleep" or improve their flight with distance.
His conclusion was "aim small, miss small" so to speak.
Read here:
https://www.longrangehunting.com/thread ... ge.144359/
In the end, zero objective evidence that bullets "go to sleep" or improve their flight with distance.
His conclusion was "aim small, miss small" so to speak.
Read here:
https://www.longrangehunting.com/thread ... ge.144359/
Every time I’ve seen this phenomenon occur... it has been traced back to parallax issues with the optic.
If you think about it.... parallax makes a ton of sense. Most Centerfire optics are set parallax free at 200-300yds. At 100 yards.... many can exhibit 1-2” of parallax, if you take the time to observe it.
This could easily account for 1.5-2” groups at 100 yards.... but then at 200 or 300, there is no parallax... so the groups drop back into their normal 1 MOA Range. Making it seem like the gun “shoots better at longer range”.... when actually, the scope just works better at longer range.
Make sense?
If you think about it.... parallax makes a ton of sense. Most Centerfire optics are set parallax free at 200-300yds. At 100 yards.... many can exhibit 1-2” of parallax, if you take the time to observe it.
This could easily account for 1.5-2” groups at 100 yards.... but then at 200 or 300, there is no parallax... so the groups drop back into their normal 1 MOA Range. Making it seem like the gun “shoots better at longer range”.... when actually, the scope just works better at longer range.
Make sense?
greenheadcaller
Beginner
- Jul 8, 2014
- 119
- 0
Songdog":2y884k1l said:
Agreed!
I have buddies who claim their rifles shoot better long, and when I observe them, the rifle/shooter does in fact shoot better long distance.
Do I believe it has anything to do with the bullet magically correcting its wayward flight = Nope, no, nada.
Do I believe there are absolutely other causes throwing off short range accuracy that are being corrected when the shooter goes long = Yep, yes, affirmative.
In addition to parallax (which does make sense), eye fatigue is often overlooked (particularly at short range with huge magnification)....and confidence, calm state, and trusting techniques are also huge parts of it imo. Many experienced shooters (myself included), trying to make small groups at short range, have a tendency to bear down and tend to abandon technique more often at short range because the target is "right there" .... and conversely settle in at distance because their/my brain knows I have to out there. RE: Confidence = if a guy truly truly believes he and his equipment are more capable at long distance then short (or vice versa for that matter), and he is generally solid technique wise ...there is a pretty good chance he will prove himself right. Our brains are great processors.
I am good with it and don't argue ... whatever is being corrected in these instances is workin for em :grin:
