Range Report Bullets shooting more accurate the further they go???

[lrgrendel]

Having a friendly discussion with a buddy regarding, specifically certain 6.5 Grendel bullets performing better at longer distances than at shorter distances. For example a certain bullet shoots 1.0 to 1.25 moa at a 100 yes but shoots less than 1.0 moa at some further distance ie 200, 300 or further.

Up to now I have only shot 308 win (175smk 1/12 twist) and have possibly seen this happen once.

Now I am about to start shooting a 6.5 Grendel 1/9 twist with 123 Hornady AMAX.

We both agree that the twist rate and stabilization is the issue but would like an explanation!

Thanks

 

[woodland-ghost]

I do this with my 6.5 and 338...low power on the scopes are 8.5 and that 1in dot becomes a big target compared to the reticle at 100 yds...I just think its all me

The further the targets are the less room for error I have...aim small miss small

I tried some 1/2 in dots and that helped, but do not have this problem on other guns, and even the same guns when I had 4-16 power scopes. Parallax can get you at 100 too, evertything makes a difference

 

[CleanMoostang]

Some bullets and rifles that I have come across are able to hold a tighter group at 200-300yd rather than traditional 100yd groupings.

 

[turbo54]

Bullets don't know where the target is, and lack the control surfaces required to change their course.

If you believe the lack of precision at 100 yards is due to random dispersion, it is not possible the bullet gets "back on course" further down along the trajectory...to do so would require the bullet to recognize it was off course, identify what way it would need to go to GET back on course, and then do something about it.

If indeed the inherent accuracy of the shooting system is better at longer range, the poor precision at closer range is not random.

 

[milo 2.0]

I'm with turbo on this. I've seen guns shoot 1/2" at 100 yards, and still be 1/2" at 300 yards, rare, but I've seen it. I don't buy into bullets going to sleep either, when I spank a 180 grain hybrid on the ass with 68.5 grs of N570, it better wake the fuck up and fly right! I guess they may have no incentive given the fact they're going to die a violent death, either bouncing across the prairie or disintegrating on steel.

It has more to do with bc, some bullets just fly better than others. We've all seen that our dope charts didn't match up, and from 400 to 900 yards we had to compensate with more up dope, but at 1000 all of a sudden match up. Beyond that it takes less. Yes of course, the data entered couldn't have been spot on, but it's the bc that was entered was wrong.
Case in point, a friend just built a 7 saum, the only bullets worth a crap he could find were 190gr Matrix's. Mediocre to 900 yards, they were like a homing missle from 1k to 1600 yards. I was impressed, not enough to buy some, but still impressed.
The 6.5 Norma 130 is another.

One thing also, the farther one shoots, the more attention to detail you're going to apply on the shot.

 

[gstaylorg]

There has been support of the notion by Bryan Litz using a 6DOF modeling algorithm that bullets can "go to sleep". It has to do with the yaw of repose if I remember correctly, but if you want to understand it better, you'll need to absorb it yourself, it's pretty heady stuff. In my opinion, it is far more likely that many cases where people claim their precision (note that you're talking about "precision" and not "accuracy" here) increases with distance are due to parallax issues. Parallax is far more critical at close range than long, and could easily result in what appear to be less precise groups at close as compared to longer ranges.

 

[Downzero]

I suspect there are two factors at work here:

1. I find it easier to aim at a 1" target at 200 yards than I do a 1/2" target at 100 yards, all else equal.

2. some say that bullets take some distance to stabilize. If so, most of the degradation in precision might be finished by say, the 200 yard mark.

The idea being, that the bullet isn't more precise at 500 yards than 100, but rather, it's more precise between 100 and 500 than it is between 0 and 100, and that increased aerodynamic efficiency results in better results on paper.

 

[leadbullet]

my best load at 100 is complete crap at 1000yds and my worst 100 yds loads is dead nuts on at 1000yds, explain that one to me plz. this was during load development on a .260

 

[sharac]

This has already been discussed and pretty much proven untrue. While there is initial yawing and general corkscrewing around the "straight line to target" or straight trajectory its so small (i believe in mr. Litzes online artice the graph thingy less than 4° and thats just yaw/pitch let alone deviation from trajectory) its almost irrelevant and it drops towards "0" drastically after 50y...

There is something else affecting your shooting @100y either shooter related, scope related or both. Even if you consider the notion of bullets not sleeping (even if powered by pricey VV and shot out off sinfully expensive custom built rifle which you've waited for 5 years and rented your wife for 2 to pay for it) it would be logical that once initial deviation has started there is no way to (consistently) nullify it after xy yards or if inherent error of sleepless bullet is so great to be noticeable at 100y it would certainly be worse at 200 etc... as flying with high AOA (angle between nose and trajectory) would induce more drag (lower BC) and thus accuracy would be worse (more wind effect, more drop) as distance grows.

 

[Greg Langelius *]

Shooters often shoot better at distances where the bullet holes are not (easily) visible. They cannot resist the urge to 'correct' their aim to compensate for perceived POI imperfections.

Some dispersion is inevitable, using it to guide the next shot is ultra-counterproductive.

Corrections should be used to counteract trends (i.e. multiple impacts), rather than correcting for individual flyers. They're not trends until a number of them are going the same way. Flyers are due to momentary shooter/gear glitches/fast transitory environmental idiosyncrasies; trends are due to shifting overall conditions and/or equipment evolutions (barrel heating, etc.).

In general, a flyer means you missed a condition change or blew a shot. Conditions are always in constant change, do better with the rest, and don't go blaming the sights. Same for bad trigger control, NPA, etc.

Once the sighters are patterning in the desired POI zone, leave the sights alone, watch conditions, and time your shots to break under conditions similar to those during final sighters

When flyers occur, hold to the original POA and 'shoot through'. Some points may fall by the wayside, but the other shooters are also experiencing the same points losses, so it evens out except for those superhuman demigods who can intuitively see the winds.

If dispersion narrows with the increase in distance (and I seriously doubt this is a true phenomenon); it is not a miracle over which to marvel and offer sacrifice, it is a factor of performance, and should come under the category of "learn your gun and how it shoots".

Greg

 

[damoncali]

You can shoot a better group at 200 than at 100. But that's not the same as the system being more accurate at 200 than 100, even on a MOA basis. That's just not how it works. What you observed is just randomness.

 

[damoncali]

my best load at 100 is complete crap at 1000yds and my worst 100 yds loads is dead nuts on at 1000yds, explain that one to me plz. this was during load development on a .260

Loads can get less accurate with distance. They cannot get more accurate. So your best 100 yard load went to hell faster than your worst 100 yard load. Often, the culprit is velocity variance that does not show up at short range that hides the fact that the good load is not actually very good at long range.

 

[dentout]

Interesting info:
Epicyclic Swerve

 

[InsidetheStorm]

Interesting info:
Epicyclic Swerve

That was a well thought out article, and seems to eliminate the "sleep" factor. I wonder if the same phenomenon would occur if a different individual shot the same rifle in the same conditions.

 

[garandman]

I've heard this is true from several sources.

Hey - if a bullet consistently groups better at 200 / 300 than 100, what can ya say?

Seems implausible, and likely relates more to the trigger puller than the gun, but I'm not gonna call people liars over it.

Science can't always explain every real world phenomenon.

 

[Cncjerry]

Once a projectile is off track, nothing but a warp in the space-time continuum is going to bring it back. Epicyclic POI shift at various ranges,yes, and if you haven't seen the air rifle videos that demonstrate this, they are incredible. Pellet is spiraling all the way to the target and hits almost exactly every time.

 

[Greg Langelius *]

I guess it's time to dust off the old parallax horse and take it out for another ride.

If you've ever looked through a scope at the target, and noticed that moving your eye around, up/down, left/right behind the eyepiece results in a corresponding shift of the crosshair across the target image; then you've experienced parallax. It is a optical illusion, characteristic of essentially all riflescopes, and it has a relationship with distance.

Unfortunately, unless your eye/cheek weld is perfectly identical for each shot, the POI will shift with each shift of the crosshair across the target image. In essence, even though the sight picture looks identical for each shot, the true POA shifts as the crosshair shifts.

Parallax can be corrected to disappear at a given distance, and many scopes allow adjustment to correct that distance to correspond with the target distance.

Most of those that do will couple this correction mechanism adjustment with the focusing adjustment, even though, technically, they are two entirely different characteristics. Unfortunately, many scope leave the factory with the adjustments not quite sync'd properly. This can be hard to detect, and is probably the most likely cause for undiagnosed issues surrounding dispersion.

If your riflescope is perfectly focused, yet the crosshair moves with the head bob/weave, your scope's parallax adjuster is out of sync with the focusing mechanism. Don't be surprised if yours is. It costs the factory more to get this perfect, and their specs are relatively relaxed in this area unless you're buying a high end optic; this is one of the reasons why high end optics cost as much as they do.

Some riflescopes, usually hunting scopes, do not offer parallax adjustment and arbitrarily set the correction for a distance of right about 200yd.

So how does this affect diminishing/increasing dispersion? A lot, especially if your parallax is set at 200yd, for instance, and you're comparing groups from 100yd and 200yd. Groups at 100 can be larger, measured in MOA, the those at 200. But the reason they are different is because of POA error related to parallax at 100 which will not be present at 200.

Generally these scopes will shoot their best group sizes at the arbitrary correction distance, with group sizes increasing at distances longer and shorter than that distance.

These group size differences are very real, yet they have nothing to do with ballistics.

Greg

 

[Captain Kirk]

Shooters often shoot better at distances where the bullet holes are not (easily) visible. They cannot resist the urge to 'correct' their aim to compensate for perceived POI imperfections.

I agree with Greg here 100%, as well as parallax. I never bought into the theory of bullets "settling" or "going to sleep".