More accurate at 200 yards than at 100 yards?

Jim T,

This defies logic to me as well. Example of why. Lets take the highest and the lowest shot from the 100 yard group. Say that they are 1 MOA apart. Now, what happens to make them converge at 2-300 yards to less than MOA. They don't have a safisticated guidance system that corrects their flight, do they? It seems to me that they would just continually get further apart. How does the top bullet in the group know to come down and the bottom know to come up? Where did gravity go? Why did it not effect them the same way? Makes you go HUH don't it /ubbthreads/images/graemlins/confused.gif. Is there such cintrifical force that it draws then together to a certain point of impact? If so, why was it not greater when the velocity and spin was higher? If the cintrifical force theory is correct, wouldn't it have a tendacy to over correct its self (I know, when the over correcting lessens this is when it goes to sleep, so to speak) To me this would indicate either poor bullet choice or improper twist rate. Both of which would lead to bad groups at any range. I have heard this discussed many times as well, but have never seen it. Not saying it ain't so, but it sure seems improbable. Now if the they were yawling a little at 100 the group would be a tad bigger but if you meassure your groups on centers this should not make much if any differance. I used to be a very avid bowhunter and also competed in lot of 3-D shoots. When you shoot an arrow it will take it a few yards for the back end to stabalize but the front portion stays heading straight. You can better tune your bow to lessen the effect. I would think that bullets would be the same in that they may yaw or pitch some but the center would be constant. In my feebal mind I would think that if a bullet wans't fully stabalized by at least 100 yards that it would only get worse as the velocity and spin slowed.

I have not heard or read or seen anything that makes this clear in my head. I have heard that it is so though from people I respect. Some things you got to take on faith I guess. Heck, I can't understand how live TV from half way acroos the planet either /ubbthreads/images/graemlins/confused.gif.

Byron
 
I have read when a bullit leaves the muzzle. It is constantly "re-stabilizing" every 3ft.(In other words...wobbling, stable...wobbling, stable, on it's AXIS, ect.)Obviously fighting, all external & projectile design forces that are applied on it as well. As it is flying down-range.
 
Last edited:
First of all I am no expert in any field.

The wobble in the bullet will say cause the bullet to go .03 to the left. Centrifugal force, momentum and wind drag will push the bullet back. Now the bullet will over correct and go .02 to the right.

Up down left or right, any wobble would continue zig zaging down the line tightening up farther down the line.

Ever see a good grouping of arrows from a poorly set up bow. They will be sticking in a tight group but all at different angles.
 
Quote:
Ever see a good grouping of arrows from a poorly set up bow. They will be sticking in a tight group but all at different angles.



Good example /ubbthreads/images/graemlins/grinning-smiley-003.gif
 
So the 300 Win Mag BlowHart sees the buck of his life at 100 yards. He would be wisely advised to run back another 100 before he takes his shot to improve his accuratecy. LOL
 
As several folks have stated, it is possible for a rifle to be "more accurate" at 200 yards than at 100 yards. Whether or not your "friend" at the range had a rifle which exhibited this characteristic is anyone's guess.

For a rifle with a twist rate of x, a bullet velocity of y, and a bullet length of z, at some point in front of the muzzle, the bullet will become perfectly stabilized - or "go to sleep" - in flight.

Where that point is from the muzzle is determined by the three variables above plus other variable factors such as barrel harmonics (related to bullet velocity, to bedding, etc.), temperature, altitude, barometric pressure, wind velocity, and so on until you have covered all external forces on the bullet.

Unfortunately, any small variations in any of the above variables will affect the point that a bullet truly becomes stable in flight. If we could isolate just one - bullet velocity, for example - all the other factors would influence at what velocity the bullet becomes stable. Keep in mind that a bullets will only fly at that velocity where all factors are lined up "cosmically" for a small portion of its flight.

So, in reality, a bullet could become more stable nearer to 200 yards and hence potentially "more accurate" than it is at 100 yards. The proof is in the target, and some BR shooters definitely will tell you their particular rifle is more accurate at 200 or 300 yards than at 100 yards.

However, thinking about it makes my head hurt after a few minutes, and I probably can't hold a rifle consistent enough for my own lack of ability to not be the biggest influence on my rifle's accuracy at any range for most HUNTING rifle/bullet combinations. - BCB /ubbthreads/images/graemlins/confused1.gif
 
There was an article in Precision Shooting that dealt with this exact subject and there conclusion was it is theorectically impossible but in reality it can happen due to a multitude of variables. They presented some very good arguments on why it can't happen and presented some theory on how it could happen but could not explain why it was repeatable. My conclusion was if it does happen nobody really knows why but it makes good academic pursuit and sells magazines.
 
OK here's my theory or WAG if you will. Think of your barrel like a pendulum. When you pull the trigger, it starts it's back and forth wobble until the bullet exits the tube. If your particular load is timed to leave the muzzle on the "inward" swing of the pendulum then the bullet will be "whipped" from the outside of the swing toward the centerline to the target. Where this whipping motion intersects could be at 200 yards. Your groups at 100 will be larger and your groups at 300 and beyond will grow also.

barrelwhip.jpg
 
Anybody that thinks the group gets tighter at further distances needs to either change their Meds or quit drinking /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/laugh.gif
 
I will stick with my original answer. The guy was full of B.S.

To address some of the comments;
1. a bullet does not have fletching at the rear of it to cause wind drag and help it stabilize.
2. Yes I have seen the yawing effect of bullets and do believe it effects accuracy. I have even seen keyholed shots from one of my rifles at 100 yds. That is the effect of an unstabilized bullet. There is no way anyone can convince me that if i had shot that same bullet at 200 yds it would have gone back to center POI.
3. I do beleive some bullets will stabilize further out than others. due to twist rate and velocity. but if that bullet is x inches from POI when it stabilizes, it will not go back toward POI. it will continue on its path till some external force alters it.
4. Every one here stated that they had read something about a gun shooting better at 200 yds than at 100 yds. I read once in grade school that this world we live in was produced by a big bang many billion of years ago. Lets see the proof.

These are my thoughts of this matter. I think sometimes we try to overanalyze things in this field. I also think that gun writers have to write articles on the latest buzz words in the shooting realm. IE moly coated bullets, breaking in a barrel, bullets going to sleep.

As for me if I have a rifle that will not shoot good at 100 yds, I will work on it till it does. sometimes that is just a change of bullets or a barrel job, whatever it takes. I wont take a bad shooter at 100 yds and say "hey I think I will just use this gun at 200 yds"

I still say the guy was full of it, as most guys that want to make sure everyone sees them usually are.
Mongo, I can make it to missouri. If you see this guy again, tell him I have a challenge for him. I get to shoot his gun and his ammo at 100 yds. five 5 shot groups. He shoots it at 200 yds. five 5 shot groups. I will pay 100.00 dollars for every group of his that beat mine. He pays me 50.00 dollars for every goup of mine that beats his.
 
Both a friend and myself have rifles (his .223 AR, my .22-250 AI Mauser 98) that tend to open up a bit at 300-325 yards and then shoot about the same at 400.

I've thought about this phenomenon quite a bit in the past, and the only answer I can come up with is that yes the bullets do have a 'guidance system' that brings them back to original line of flight, namely its gyroscopic spin (consider that inertial guidance systems on rockets, aircraft, etc. have high-speed gyros spinning in them).

If you've ever played with a simple kid's top, you'll notice that when you get one spinning, it will stand on its point for a moment (motionless but for spin) then may wobble a bit, then settle down to be 'motionless' again.

What is instructive here is the behavior of the point of the top (the part in contact with the floor) during this wobble. Sometimes you will see it go from 'motionless' to describing a spiral circle, that is sort of corkscrewing around in a bigger and bigger circle, until the top 'goes to sleep' as we like to say about bullets.

At the point when it goes from more-and-more-unstable (the point making bigger and bigger circles on the floor as the top wobbles) to going more-and-more-stable, the point will keep circling, but suddenly the circles get smaller and smaller until it 'goes to sleep' and spins with the point staying 'motionless' in one place.

What is interesting is that frequently the point will wind up back at the center of its own circling - that is, it EXACTLY REVERSES its path from 'divergence' (going unstable) to 'convergence' (coming back to 'rest').

That is, whatever motion the top (or bullet) makes in going 'unstable' slightly (and with a bullet it's like a long corkscrewing motion as it flies downrange), is PERFECTLY REVERSED as it becomes stable again.

I believe this is the mechanism which 'brings the bullet back' to its original line of flight. The bullet does not actually DIVERGE at some angle to its original line of flight, but rather corkscrews AROUND its original line of flight - going from straight flight to circling corkscrew which surrounds its original flight line (and stays parallel to it), then when regaining stability, reversing this motion (circling tighter instead of bigger) back to original flight line. The groups while corkscrewing will be big, but the groups before and after this brief period of instability will be smaller.

Not sure this is the case, but I can clearly remember this sort of behavior by the point of a top going through a wobble phase. It displaces in circles as it goes slightly and temporarily unstable, them reverses those circles as it regains stability and winds up pretty much back where it started. This behavior by a bullet is the only thing I can think of that matches observed results on a target.

Is everybody more confused now?
Maybe it's time to post that dead horse picture again.
 
Weather it seems impossible or not it is pretty easily demonstrated with the VLD bullets. I have a 280AI shooting 180VLDs and a 22-250AI shooting the 77VLDs that consistently shoot less MOA at 300 than 100.

A lot of the logic used to explain why it is impossible starts out with a false assumption. It assumes the bullet goes in a straight line and is curved by wind and gravity. This is not true, bullets actually go in a spiral that is curved by wind and gravity.

Jack
 
Jack, your mention of a spiral path kind of dovetails with my thinking above. I'd be interested in your opinion of my ramblings above in this regard. Can't think of anything else that matches 'target truth'.

Mad Mountain Pete
 
Yep...like I said change the meds or quit drinking...that'll clear up the delusions for sure /ubbthreads/images/graemlins/grinning-smiley-003.gif /ubbthreads/images/graemlins/grinning-smiley-003.gif /ubbthreads/images/graemlins/grinning-smiley-003.gif
 
Meds?? Drinking???

Heck, I got this way NATURALLY!!! Meds and booze would probably be an improvement.
The smell of gunpowder helps though....

B-B-B-B-B-B-B-B-B-B-B-B-B-B-B...(finger flipping across lips)
 
17 shooter:

Just a comment on your statement about a 100 yard rifle versus a 200 yard rifle:

Some BR shooters will actually load an accurate rifle differently for different distances. For example, the very accurate load they use at 100 yards may not be as accurate as a different load is at 200 yards, so they will use different loads for each distance. Hence one load stabilizes a bullet very well at 100 yards and another load stabilizes the same bullet at another range or distance like 200 or 300 yards.

In other cases, a serious BR shooter may have a rifle that is most accurate at 100 yards and another rifle that is most accurate at 200 or 300 yards, even though both of them are very accurate at all ranges in comparison to a non-tuned rifle.

Also, no amount of magic will stabilize a bullet that is totaly unstable (key holes) at 100 yards. In those cases, the bullets has lost its gyroscopic effect and will go where it "chooses" as it tumbles - whatever the distance may be. What is being discussed here is a rifle/bullet combination that is generally very gyroscopically stable at all ranges but may be more stable at one or more ranges than others.

Well, time to go take my meds and mix my 23rd Scotch and water for the evening. Take care.

- BCB
 
Back
Top