Discussion in 'Rifle Country' started by srawl, Mar 29, 2017.
And, depending on the scope, less parallax at the longer range.
Barrels whip and wiggle while bullets go through them just like fishing rods when smacked with some external force.
It's not effected any different by gravity or wind. Those are the only external forces. Unless it's a steel bullet and flies close to a magnet.
Outdoors, you sometimes get a situation where wind will cancel muzzle dispersion, and as a result you'll see a smaller group on the farther target. But it's a small effect, and it never happens consistently, only randomly. Measure the average group, and they always get bigger.
So then, you must not believe in positive compensation for far range bullet drop when bullets leave on the muzzle axis up swing.
And then tuners on barrels used to refine barrel whip to make compensation better is unscientific voodoo.
Where's my Llama Bob doll? I just sharpened all my pins. My voodoo suit just got back from the cleaners and I'm donning it as I type.........
This thread shows a weak grasp of external, and internal, ballistics coupled with barrel mechanics in general.
That's fine with me. Thousands of others think the same as I. We understand your disbelief.
The fact that the Brits dealt with it for over 5 decades with their SMLE 303's loaded with Cordite producing huge muzzle velocity spreads but shooting smaller groups past 800 yards than at medium ranges has no bearing whatsoever.
I don't think you understand why and how barrels wiggle while bullets go through them versus bullets' barrel time across muzzle velocity spread.
what a drag!
Grab your SMLE and stash of .303 Cordite loads and get win free all expenses paid trip to Brian Litz's lab/range to prove him and the rest of us wrong!
The proposition for positive compensation is based on the fact that when any given batch or type of ammunition is chronographed, there is a always a spread in muzzle velocity observed about a mean. As a consequence, there will be a vertical dispersion in the fall of shot at the target, as the slower bullets in the sample take longer to travel down the range and so drop further than the faster bullets. It is easy to compute what the vertical dispersion should be for a given batch of ammunition due to the observed spread in muzzle velocity.
Curiously though, it is also often - if not usually - observed that the calculated vertical dispersion is not evident on the target. To explain this observation, the concept of "positive compensation" is invoked. It is generally recognised that the shock of the recoil forces in the rifle generate transverse vibrations in the barrel. For positive compensation, it is envisaged that the bullet is exiting the muzzle during an upward swing in the vibration at the muzzle, such that faster bullets (which arrive at the muzzle slightly earlier than slow bullets) are launched at a slightly lower angle into their trajectory than slower bullets. This will tend to reduce the vertical dispersion in the group at the target resulting from the variation in muzzle velocity. And if the upward swing in the muzzle is exactly right, there will be complete positive compensation as the trajectories of bullets across the entire spread of muzzle velocities all meet at the same height on the target at a given range...
Am I the only one in this place that understands the principle of positive compensation and has shown proof it exists?
There's no point in arguing what causes the coloration of a pink unicorn, if no one can provide evidence pink unicorns exist.
As do thousands who use tuning weights on their barrels. The Browning Boss properly adjusted also positively compensates.
You just keep repeating yourself when what you're saying has nothing to do with what everyone else is talking about.
Barrel harmonics can make a difference in accuracy.
It can't make a gun shoot a smaller group at a longer distance than it will at a shorter distance.
It improves accuracy equally at all distances.
No one has disputed that fact.
It simply has nothing to do with this topic.
You're the only one who thinks it relates to what is being discussed.
Do you still shoot?
The BOSS shrinks groups both horizontally and vertically. If it worked by compensating for differences in bullet drop, it would only shrink them vertically.
The barrel typically vibrates both horizontally and vertically, probably in an elliptical arc. The BOSS changes the resonant frequency of the barrel so as to time the bullet exit to be near a slow moving part of the arc. Bullets that exit near this time will group more tightly than bullets that exit during a fast moving part of the arc. This happens for two reasons: 1) The barrel is pointing in nearly the same direction in spite of variations in bullet transit times, and 2) The slow moving part of the arc imparts less transverse speed to the bullet.
There are a lot more forces at work...
Lift (Cross Wind Force)
Pitch Damping (What makes the cone of accuracy shrink as distance increases)
So yes, a properly stabilized bullet will have a decreasing cone of accuracy as it stabilizes out...
Here are the basics:
Hope this helps...
Gravity: Listed in my post.
Coriolis Force: A real factor, but not a real force. It's a fictitious force that arises from the fact that Earth is not a true inertial reference frame.
Centrifugal Force: An internal force, not an external one. Can't change the path of the bullet, per Isaac Newton.
Drag: Listed in my post.
Lift: Vector component of drag.
Magnus Force: Exceedingly tiny, but real.
Transverse Magnus Force: Vector component of Magnus Force.
Pitch damping: Vector component of drag.
All of the physics are real.... Their effect is minute, but still true... A properly stabilized bullet will settle into a small cone of variation over time... While better optics will increase the accuracy, they have no effect on the bullet and that is how I interpreted the question.
Fats are you a pool player?
Back in the day when I took it seriously, I was known as Mr. C.
Paid for a Brunswick Gold Crown and a Preditor cue...
Obviously you didn't go to the site listed ...
Separate names with a comma.