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Math is awesome...I really do like math, because it quantifies so many of the assertions and assumptions we make. The problem with math, even this kind of stuff where we actually can take everything into account and get REALLY close, is that math ain't what matters.

In the vast majority of situations, the BC of the bullet, MV at the muzzle, or the fancy turrets on your scope don't mean a darn thing...if'n you can't shoot at 500 yards. By that, I mean two different things, really. I mean, if you can't go out to a range and SHOOT those bullets at 500 yards, and if your shooting abilities aren't up to shooting accurately at 500 yards, none of this math or theory means a darn thing. You will not, CAN NOT, "know" what those bullets will do at 500 yards, until you shoot them at 500 yards. Perhaps much more to the point: If you don't have the skills to shoot at 500 yards, you'll never know what the rifle/load/scope/bullets are capable of doing at that distance.

And so, it always comes down to the same thing, no matter what the math says: GO SHOOT THE DARN THING! ;)
 
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Exterior ballistics, as broom_JM has said, Can use the information entered to give close approximations of what should happen if all the input is correct. The problem arises that actual conditions change. Winds, temperature, barometric pressure and air density can change from one shot to the next. On top of those considerations is the shooter. An imperceptible twitch or a change in the grip or position in which the gun is held can vary at least as much as the external conditions. None of us are super-human enough to shoot at our very best all the time. Training properly and consistently helps but we will never be perfect.
Use the math to predict the approximate position of the bullet and then fire it to make it as close as you can. I like shooting small groups, you might even say I am fanatical about it but as my age progresses I am less able to maintain that discipline for longer periods of time. I practice more often than most but I have to in order to maintain what accuracy and consistency I still have. My son commented at the range recently after I spent some time coaching him and his wife by remarking about a five shot group I shot with, "look at that group!". It was a good one ragged hole group but not exceptional in any way. I just wanted them to know that with practice they could shoot as well as anyone. We then went back to basics.
 

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Well, this may sound funny coming from the math source, but by bringing in factors the OP has already settled, you guys are making it way too complicated. The information we have is that zero was established with the rifle at 200 yards. So the baseline shooter factors (except for wind doping skills) and the gun barrel's "vibration" response to the ammo, and other things that can upset an exterior ballistics program result were already accounted for. Was the drop information the OP generated correct? We don't know since he didn't name the bullet or give the muzzle velocity or report the atmospheric conditions. But I don't think he'll be far wrong.

All we are left with (and all the math solves) is a very simple geometry problem. At any given magnification, each click of the sight adjustment moves the cross-hairs the same amount in the field of view, regardless of what distance the target is. So the effect of a sight adjustment, in inches of POI, is only about how big each inch of the target appears in that field of view. Below, omitting the cross-hairs, is how big the same target looks at 200 and 500 yards. The faint blue dotted lines show how much distance the same sight adjustment will affect the point of impact at the two ranges.

In particular, I made the two zeroes on the rule level and made the ruler along the edge of the target 33 inches long, so I could pull the next line off at 32.4 inches so you can see how much the same sight adjustment will move the point of impact at 200 yards. It's a tiny fraction under 13". That's all that matters to this problem.

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I can understand pictures!

Thanks unclenick!

RJ
 
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We are shooting a .300 RUM
Zero at 200 yards.
According to various ballistic calculators.
At 500 yards it calculates a bullet drop of 32.4 inches.
A custom elevation turret was ordered to all the correct specifications to a very reputable company.
Gave ALL applicable data, velocity, bullet weight, BC, etc.
Set 2 targets at 200 yards. The top one was exactly 32.4 inches above it.
Turned the turret to 500 yards, fired at the bottom target.
I was assuming the bullet would hit the top target, right on.
Not on the paper and no idea where it's hitting.
Am I making the wrong assumption, or is there a problem with the turret, or even the ballistic calculator data?
Any and all responses would be appreciated.
Thank you!
I weigh all bullets for consistency, then I use a ballance scale to weigh charge, set up targets every 50 yards from zero out to see bullet trijectory till I achieve my quest. To me a zero is in moa same bullet hole or clover leaf @ 300 yards! If you are not consistent @ 300 you will not achieve 500 yard zero. Track and record your turret adjustments as you go. I wound not trust any one not even my Mother.
 

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Blindeyed,

I think you may be confusing accuracy with precision. Zero just concerns accuracy, not precision. It just means getting the average bullet hole location to go where the sights are looking at zero but imposes no limit on group size. Precision is how close to that average location you can get with every shot and is often improved by your loading practices. But you can have zero for either low or high precision shooting.

Unfortunately, weighing bullets and powder charges are not enough to guarantee precision. Indeed, many modern match bullets are so consistently made, you can't find a weight difference between them without higher resolution than loading scales usually provide. But beyond that, longer ranges need low velocity spread which requires primers to be seated properly and within about a thousandth of an inch of the nominal amount of anvil compression into the priming mix. Bullets need to enter the bore lined up straight, and that involves the case symmetry, which can require brass processing to achieve, and the seating process being perfectly straight. The motion that is induced in the barrel by recoil needs to repeat consistently which means selecting a load that causes the bullet to leave the muzzle at the right phase of that barrel movement so it isn't changing dramatically enough for shot-to-shot velocity variation to cause enough difference in the muzzle direction at the moment the bullet clears the muzzle that it changes the point of impact. Of course, before all of that, the gun has to be suitably accurate and the shooter has to be good enough to take advantage of that, something that is tested most especially in a gusting crosswind. There is much to be done.

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