Why groups at long range are the same as close range.
- Thread starter Maple57
- Start date
1) Brian Litz’s take on accuracy vs distance:
mostly proportional to flight time for a given load.
This means that a 0.5 MAO 300m load should be a little less accurate at 600m and significantly less accurate at 900m.
For example, a 600y 1/4 MOA load is measured as 1000y 1/3 MOA.
2) David Tub’s opinion on weird accuracy results: always zero and measure groups at parallax free distance! (I’ve tested that one and you might be surprised)
mostly proportional to flight time for a given load.
This means that a 0.5 MAO 300m load should be a little less accurate at 600m and significantly less accurate at 900m.
For example, a 600y 1/4 MOA load is measured as 1000y 1/3 MOA.
2) David Tub’s opinion on weird accuracy results: always zero and measure groups at parallax free distance! (I’ve tested that one and you might be surprised)
Yeah - I don't really buy that. That would imply that the shooter would be more casual and apt to be careless at shorter ranges because of a bigger target.
Because of ammo costs and time spent to load quality ammo, I try to exercise the same shooting care and consistency at all ranges and if anything my target at shorter ranges is more sharply defined (a sharp right angle of a target for instance) with comparatively higher magnification.
It still boils down to the fact that quite often MOA is the same or sometimes better at distance. You don't buy the bullet stability concept - fine - but I don't think it has anything to do with shooters shooting more carefully at longer distances.
Last edited:
This may be old news, but some readers may be unfamiliar with it. In late 2014-early 2015, Bryan Litz propose a "Shoot Thru Target" Challenge. It was to provide a challenge to shooters to prove that better results could achieved at further distances than at closer ones. As of summer 2020, no shooter had been able to meet the challenge. See h t t p s://www.longrangehunting.com/threads/applied-ballistics-shoot-thru-target-challenge.144359/page-11 and h t t p s://forum.accurateshooter.com/threads/applied-ballistics-shoot-thru-target-challenge.3861880/
The conclusion from this seems to be that bullet dispersion occurs and bullet convergence doesn't.
As a note of interest in .22LR testing at indoor test tunnels, there have been more than a few incidents where better results are recorded at 100 meters than at 50. What's important to remember is that in these tests, the exact same rounds are measured electronically at both distances. There is no paper target to interfere with the flight of the bullets. The same five or ten rounds are recorded at both distances. This eliminates the problem of evaluating the performance of different rounds because in .22LR it's not possible to be sure that different rounds from the same lot of ammo will perform the same way.
It's likely that the soft lead of .22LR ammo doesn't always have the same center of gravity and so may produce different results at different distances. Of course it's not possible to predict this kind of performance. In other words, a shooter cannot know in advance when a group will be smaller at 100 meters than at 50.
The conclusion from this seems to be that bullet dispersion occurs and bullet convergence doesn't.
As a note of interest in .22LR testing at indoor test tunnels, there have been more than a few incidents where better results are recorded at 100 meters than at 50. What's important to remember is that in these tests, the exact same rounds are measured electronically at both distances. There is no paper target to interfere with the flight of the bullets. The same five or ten rounds are recorded at both distances. This eliminates the problem of evaluating the performance of different rounds because in .22LR it's not possible to be sure that different rounds from the same lot of ammo will perform the same way.
It's likely that the soft lead of .22LR ammo doesn't always have the same center of gravity and so may produce different results at different distances. Of course it's not possible to predict this kind of performance. In other words, a shooter cannot know in advance when a group will be smaller at 100 meters than at 50.
Munkey1973
CGN frequent flyer
- Location
- Regina, SK
I don't know the validity of the source of this photo (i.e. has it been photoshopped to look like this ?)
Let assume that the photo is in fact legit.... the person taking the photo had caught this image at just the right time with the proper camera and lens.
The reason that the vapour trail appears to be bigger closer the muzzle than it is further away (i.e. the cone is narrowing down range) is likely due the fact that the vapour trail dissipates as the bullet moves away.
It would like looking at the vapour trail of a jet the the sky.... the trail is narrower closer to the jet's engine and fans out the further you look back at its trail.
Like the wake that that a boat makes in the water.
I shake my head whenever I hear this notion that "some bullets will stabilize better the further that they go out"...... No bullet exhibits this kind of magical behaviour that somehow defies the laws of physics.
Every bullet has it best stability 0.0000001 of an inch after it clears the barrel..... the stability of that bullet goes down (exponentially) as it gets further away from the muzzle.
If someone manages to 5 shots into a 1" circle at 100 yards, and then they manage to do 5 shots of the same load & gun into a 5" circle at 1,000 yards on the same day...... then projectile did not magically "tighten up its cone" somewhere between 101 and 1,000 yards. The shooter either got lucky, or was more focused on their shooting at 1,000.
Munkey1973
CGN frequent flyer
- Location
- Regina, SK
Saying that bullet ABC shoots tighter groups at 600 yards than it does at 100 yards, would be equally impossible as saying that bullet XYZ increases it velocity as goes down range
Last edited:
turbo_bird
CGN Ultra frequent flyer
- Location
- Kamloops, BC
There's also the fact that things further away from a camera will look smaller than things that are closer. Different lens focal lengths will show a different perspective, so unless you know what lens and camera were used, as well as being able to measure accurately and knowing how far away the vapour trail is from the camera, you can't just look at the photo and say the spiral is smaller further away from the camera.
Kristian
Anyone who has been on the forums for any amount of time will have come across heated arguments about groups getting better down range than at close range.
I myself have experienced groups that support such a theory (at first glance) but I don't believe it is necessarily that the bullet started flying more straight or more true.
If you look closely at this image, you can see the trace or vapor trail is spiral. I think this spiral explains much of the argument and debate.
I think the reason group sizes can miraculously reduce in size at long range is simply a condition where this spiraling effect becomes synchronized over a number of shots for some un-explained condition, or perhaps just luck.
I also think that if the target was moved forward a few yards, the group would impact somewhere else within the overall spiral pattern. (I have tested for this and evidence inconclusively supports the theory.)
There may also be a rhythm to the spiral where it goes into and out of phase at different distances.
I also suspect that close range groups may not have been in flight long enough to synchronize into a repeatable spiral pattern (out of phase) and impact randomly along the arc of the spiral to produce the larger group.
A hummer is a barrel that simply produces a really small spiral and thereby, really small groups.
All of this in addition to natural dispersion in accordance with the usual ballistic factors.
I am fascinated by this picture. I have been reading Litz and others on long range theory and practice for years. Several authorities on the subject have suggested using vapour trails to "track" your LR shots. Yet, I have never seen one in a variety of weather conditions.
Several posts suggested that this shot involved a jacket separation. That aside, have others observed these trails? Better yet, does anyone have another pic of one?
- Location
- NOVA SCOTIA, CANADA
Never seen a vapor trail with the naked eye but often see the bullet when shooting long range thru the scope.
Aim small, shoot small.
I surprised myself and shot a group tighter at 300 then I did at 100 when I was sighting in a scope last weekend.
As a photographer that takes photos at firearms events I'd call the picture B.S.... lets see some more spiral bullet pics, must be thousands out there...
I surprised myself and shot a group tighter at 300 then I did at 100 when I was sighting in a scope last weekend.
As a photographer that takes photos at firearms events I'd call the picture B.S.... lets see some more spiral bullet pics, must be thousands out there...
You’re looking for the bullet’s wake for a short time before it hits the target.
http://bulletin.accurateshooter.com/2017/01/how-to-spot-trace-the-bullets-wake-signature/
http://bulletin.accurateshooter.com/2017/01/how-to-spot-trace-the-bullets-wake-signature/
It is generally quite easy to see, but you may need to train yourself to see it.
Shooting F Class is a great way to learn because you are firing from a stable position and the time of flight is long enough to see trace very well.
It does depend on weather though. Dry days make it harder to see because there is low humidity to compress. It can also be hard to see on windy days because the wind can quickly blow away the condensed air which reduces the time you can see it.
The trick is to look above where you are aiming and watch for the silver streak to come down.
Damp days with low wind are ideal for spotting shots.
