9 o'clock vs. 3 o'clock wind drifts different with same wind velocity???

[Bart B]

I could see it. Measure it? Not at that range. This is why we call it judging the wind.

That's more realistic. When you said you could "see" the wind speed, I didn't believe that.

The bottom line is that we judge and calculate.

Me, nit picking? And because you calculate or judge spin and coriolis drift, that's not nit picking?

 

[paphil]

Bart, My 6.5-284 is 0'ed at 300 yards and takes exactly 22 moa at 1000 feet elevation and 75 degrees for a 1k shot . It has a BC of .615 with berger bullets and a velocity of 2942 fps. First group in competion last year was a 4.21" five shot group at the Harry Davis memorial club in W. Va. (Check the records on their website) Haven't shot that small sense then but did kill 4 groundhogs at 1200 yards with a total of 5 shots. The gun shoots better than I can. 2 degrees works for me. It doesn"t matter if the scope is not square to the gun, or even if the reticle is square. What must be rotated is the adjuster mechanism inside the scope. Some reticles can be rotated as much as three degrees out of alignment with the adjustment mechanism. I believe this accounts for some guns having more or less than the average 9" that is mentioned. I recently talked to a fellow at the DSC show that claimed 9" left drift. Shoot the vertical test at 100 yds and see if you are right , left or dead on . Dial 100 and shoot, then dial 1000 and shoot at the same mark. Group should fall on the vertical line to have the reticle and mechanism square. I want mine to be about 3/4 to 1 inch left. This pretty much accounts for about 9 inches of drift. Just reread this and don't mean to turn anything inside scope just to be aware that without testing, canting could help or worsen depending on how the reticle alines with the mechanism inside the scope. It is NOT a user fixable problem!

 

[Michael Eichele]

And because you calculate or judge spin and coriolis drift, that's not nit picking?

From my point of view, no.

Why?

Because a deer's kill zone is 8-12" big depending on the deer. If my SD/CE is 10" at 1K, I have just made a miss or worse, a bad gut shot. For simplicity sake, lets say there is no wind today. I take a shot at a deer at 1K and have 10" of drift, even on a 12" kill zone, I have missed the zone by 4". To me, taking into account all the variables and eliminating them (nit-picking) is the only way to make the best shot possible. Now factor in the wind. Between a small miss-judgement of the wind coupled with SD/CE and lack of adjusting for it, the miss is even greater. Sure, one or the other could cancel the other out at times. On the flip side, the times it does not means that they have compounded eachother.

I can understand not giving a crap about factoring these variables in for a target shooter where the life and well being a piece of paper is at stake. For a longrange hunter, if SD/CE are not important and adjusted for, they (IMHO) dont care about the well being of the game they hunt. Its one thing to kill the game or at least stack ALL the odds in the favor of a clean kill. Its another to take into account only some of the variables and create high odds of wounded losses and game having to suffer. Unfortunately, we cant legislate how much a hunter does or does not care about the game he hunts.

 

[ken snyder]

This is a real good thread! But now stuff is starting to go "swoosh" right over the top of my head! The S.D. isn't confusing me and I know the earth is spinning about 1500 fps at the Equator and about Zero fps at its axis and that N. S. E. and W. make a difference but what do I do about it here on the 45th half way from the equator and half way to the North Pole. Is my CE where I do most of my shooting so small that I am just throwing the difference into incorrectly doping the wind or is it already so small that it really doesn't matter. I'm talking first shot here and not the ability to correct the second shot or those there after.

 

[SBruce]

This is a real good thread! But now stuff is starting to go "swoosh" right over the top of my head! The S.D. isn't confusing me and I know the earth is spinning about 1500 fps at the Equator and about Zero fps at its axis and that N. S. E. and W. make a difference but what do I do about it here on the 45th half way from the equator and half way to the North Pole. Is my CE where I do most of my shooting so small that I am just throwing the difference into incorrectly doping the wind or is it already so small that it really doesn't matter. I'm talking first shot here and not the ability to correct the second shot or those there after.

Just my opinion, but since CE can be calculated (Exbal says 2-3" right at 45 lat. at 1000 yds) It seems prudent to me at least to account for it, especially when attempting 1st round hits. IMO, doping the wind especially if it's variable, is tough enough without ignoring the things that are proven to exist and cause an effect.?...........again, just an opinion, I don't shoot at 1000 yds often enough yet to have even a strong opinion.

I think it's a great thread too, it's nice to have some folks who shoot 1000 yds quite often chime in here. Competition or hunting either one, my interest in long range hunting was born from competition shooting.

 

[Michael Eichele]

IMO, doping the wind especially if it's variable, is tough enough without ignoring the things that are proven to exist and cause an effect

^^^^^Amen!^^^^^^^^^^^^

 

[ken snyder]

I agree with you guys that it is important to take eliminate as many goofas as possible and make it as simple as possible. I get to shoot a 1800 yd Milk Jug challenge with the guys quite often which is skewed because it is always the same target until it grows over and we need to find a new one and that in fact is target shooting. However on first shot connections even at yardages as close as 1K being off a couple of inches of wind drift is absolutely no different than not correcting for CE. Ive got to shoot with some pretty good teams and have seen second shot corrections a lot bigger than a few inches and even corrected further off the other direction. I agree 100% with S.D. but still don't see the need to correct for CE any more than correcting elevation for moon phase. I will continue to look at CE and see if I can put it together into something that makes a difference for me. So here I am wondering because some people will call a burnt piece of chicken blackened and give an elaborate recipe to do so while others just burn it.

 

[Bart B]

For what it's worth, here's some insight as to what the very best (NRA classified High Master, top 3%) 1000-yard bullseye shooters do with their first shot. Even when they've been shooting the same load in the same rifle for the previous 2 or 3 days. And all at the same range, in the same direction, at the same altitude and virtually the same atmospheric conditions...except for wind. So they've got their rifles well zeroed.

After estimating the cross wind speed by watching the mirage at different points down range through their spotting scope, they'll make a windage adjustment to correct for it then fire their first shot. No more than 10% of them will put their first bullet inside the 10-inch X-ring.

I don't believe long range hunting folks are any better. I hear about their kills, but never anything about how far their first shot misses the intended 10-inch vital area on game. I also believe the best of them are as good as the best of the long range bullseye busters.

 

[ken snyder]

I hope that I'm not giving the impression that I do not believe in CE or its ability to change bullet flight. I honestly feel that CE should be considered but I do not have the ability to demonstrate it to myself to a degree any where near enough to observe it and learn it. I can take it as a useful fact and add it or subtract it. On the calmest November morning with Cigar smoke going straight up virtually, no wind, the ground and air at the same temperature and the sun not visible through the clouds and virtually no thermals. If I were to shoot and immediately turn around and shoot the opposite compass heading there would still be enough wind drift and differences that I personally would not be able to demonstrate its existence to myself - How can a guy learn from something that ellusive. I love November mornings because for about 20 minutes in the morning it is as close to shooting in the bottom of a Salt mine as I am likely to experience and I still am not capable of shooting the first round to a degree accurate enough to learn or use CE

The bottom line for me is that I can't demonstrate it to play with it and if I can't play with it I can't learn from it and what I haven't learned I can't use

 

[Michael Eichele]

I agree with you Bart. That said, this is where every long range hunter should know his/her limitations and stay within them. Windage is a huge part of the proccess. It is typically pretty evident which wind is 'manageable' and which is likely to lead to an error. There is nothing wrong with passing on a shot when conditions don't feel right. We (I) don't have too take every shooting opportunity. I am picky and only take the shots I know I can make. Can't say I have always hunted this way, but that is how I have done it for the last 9-10 years.

 

[Michael Eichele]

I If I were to shoot and immediately turn around and shoot the opposite compass heading

Just to clarify, either direction, you will still see an impact to the right (in the northern hemisphere).

 

[ken snyder]

Thank you! That clears up why I don't see it or consider it and understand why it is important to some but irrelevant to me. For clarification I use different rifles while hunting and each of them set up for expected yardages and animal body sizes. So now I know why and will definitely pay some attention if I should choose to build a yardage non specific rifle. Even with my hunting partners we do not double up on rifle design capabilities. One of us always have a mid range rifle while the other has had either a short range or a long range set up ( CE unknowingly already accounted for) Luckily for me the egg on my face only wears for a short while!

 

[shortpants]

Just to clarify, either direction, you will still see an impact to the right (in the northern hemisphere).

I've been following and understanding everything until you said that Michael. Could you explain that part to me or at least try?

 

[Michael Eichele]

I've been following and understanding everything until you said that Michael. Could you explain that part to me or at least try?

Let's say you are sitting on the north pole shooting at a target on the equator. Because the target is moving to your left, the bullet impacts to the right of the moving target. Spin drift aside, the bullet moves in a straight line. The bullet did not drift from the target, the target moved.

Now let's say you are on the equator shooting a target on the north pole. You are moving at high speed from left to right in relation to the target. So is the bullet you are launching. Since you are moving from left to right so is your bullet. The target is stationary since it is on the earth's north end axis.

Granted the above illustrations are not possible. It just shows you the principals behind it.

Envision shooting at a stationary target from a moving vehicle. If the rifle fired as the target was in the crosshair, you would miss the target in the direction you were traveling because the bullet is also moving laterally as well as forward. Now envision that target you were shooting at shot at the vehicle you are in. If the rifle fired as the vehicle was in the crosshairs, the bullet would miss in the same direction as the vehicle was moving from. The vehicle is moving from left to right. The bullet would impact to the left of the vehicle. You in the vehicle are moving from right to left from your percpective. Your bullet would impact to the left from your percpective. In both cases the bullet impacted left from the shooters perspective.