How much does elevation change POI

[KClark91]

Coming from the east coast to Colorado for rifle season elk. I searched ballistic charts to calculate difference for my 7rem mag at 0 to 9k and it’s around .5moa adjustments high at 9k. Does anyone have any real world experience shooting long range coming from the east coast or lower elevation.

 

[Macintosh]

Sure, I live on the east coast and generally shoot and hunt here around 2000’ DA. When I travel west to hunt I have done so between 5000’ and 11000’ elevation.

When I check zero after flying west, my 100-yard zero generally does not shift—if it does, its from the baggage handlers, not the change in elevation.

You’ll see an increase in how far off your low-elevation dope is as you go up in DA and as you increase range. Looking at 2 rifles, a 270 and a 6.5cm and comparing 2000’ to 9000’ DA, at 300 yards my dope is off either less than .1mils or .1 mils, and both rifles are off .2 mils at 500 yards (So low elev solution is 3.1mils, 9000’ solution is 2.9, difference is .2mils). That equates to about .35moa or less at 300 (about 1.1” impact distance) and about .75moa at 500 (about 3.75” impact distance).

Keep in mind that amount of error is in addition to the precision of my equipment and my wobble, so it’ll very easily cause a miss/bad hit on a deer-sized target at 500 yards that would otherwise have been a good hit. At longer range it’ll be worse.

 

[SDHNTR]

I get the

Coming from the east coast to Colorado for rifle season elk. I searched ballistic charts to calculate difference for my 7rem mag at 0 to 9k and it’s around .5moa adjustments high at 9k. Does anyone have any real world experience shooting long range coming from the east coast or lower elevation.

Your zero is one issue. And may be minimally effected. Is that what you are asking?

Your long range trajectory is another matter entirely. Consult your ballistics solver.

 

[Megalodon]

Sure... you don't need as much elevation adjustment at altitude. You're ballistic calculator will tell you exactly how much. Also your windage holds will change.

 

[KClark91]

Sure... you don't need as much elevation adjustment at altitude. You're ballistic calculator will tell you exactly how much. Also your windage holds will change.

I

Sure, I live on the east coast and generally shoot and hunt here around 2000’ DA. When I travel west to hunt I have done so between 5000’ and 11000’ elevation.

When I check zero after flying west, my 100-yard zero generally does not shift—if it does, its from the baggage handlers, not the change in elevation.

You’ll see an increase in how far off your low-elevation dope is as you go up in DA and as you increase range. Looking at 2 rifles, a 270 and a 6.5cm and comparing 2000’ to 9000’ DA, at 300 yards my dope is off either less than .1mils or .1 mils, and both rifles are off .2 mils at 500 yards (So low elev solution is 3.1mils, 9000’ solution is 2.9, difference is .2mils). That equates to about .35moa or less at 300 (about 1.1” impact distance) and about .75moa at 500 (about 3.75” impact distance).

Keep in mind that amount of error is in addition to the precision of my equipment and my wobble, so it’ll very easily cause a miss/bad hit on a deer-sized target at 500 yards that would otherwise have been a good hit. At longer range it’ll be worse.

Yea in my ballistic calculator for 9k if I adjust .5moa low my trajectory would be 500 1.5” high and 600 3.1” high compared to where it’s sighted in now now. Just wondering how accurate the calculator is for elevation change

 

[Megalodon]

Do you have a reason not to trust your calculator? Are it's solutions accurate at the distances you currently shoot?

 

[SDHNTR]

I think I understand what you are asking. Does your solver have an “atmospheric zero” feature? Turn it on and it will accomodate.

 

[Macintosh]

… Just wondering how accurate the calculator is for elevation change

IF your inputs are good, any of the good calculators will be good. But only if your inputs are good.

 

[KClark91]

I think I understand what you are asking. Does your solver have an “atmospheric zero” feature? Turn it on and it will accomodate.

I can input elevation and it calculated drop at the distances. If I adjust .5moa down and add 9k elevation the trajectories are very similar. Just not sure how accurate the elevation change is.

 

[SloppyJ]

If you've trued your dope out to 1200yds or so has anyone had any issues with your solver at elevation?

I live around 1200' and will be hunting around 9000'. I'm using the built in AB solver in my Gen 2 Kilo 10ks and it's been money so far if I do the work to tune it and verify. But I haven't tested the elevation feature on it yet. It does record temp and elevation to calculate the DA. I want to put trust in it but it's hard when you haven't personally done it.

 

[Megalodon]

I can input elevation and it calculated drop at the distances. If I adjust .5moa down and add 9k elevation the trajectories are very similar. Just not sure how accurate the elevation change is.

wtf are you talking about. Don’t change shit. Keep your zero where it is. Don’t dick with atmospheric zero. True your data up however you choose on your home range. When you get to where you’re going to hunt put in your new atmospherics and dial what it tells you. If you run a hard card, make it once you get there.

 

[SDHNTR]

I can input elevation and it calculated drop at the distances. If I adjust .5moa down and add 9k elevation the trajectories are very similar. Just not sure how accurate the elevation change is.

Ok, now you lost me again. I don’t understand what you are questioning. Do you doubt your ballistics solver? Why? It’s math, there’s nothing to question.

 

[mxgsfmdpx]

There is no need to adjust your 100 yard zero, anyone who tells you do to so is misinformed. Make sure it is still zeroed from the travel and hunt on.

Adjust your home range confirmed DA hit inputs to the current DA. If your first time shooting at a certain distance is on a hunt and at an animal, you are doing thing backwards.

 

[KClark91]

Do you have a reason not to trust your calculator? Are it's solutions accurate at the distances you currently

There is no need to adjust your 100 yard zero, anyone who tells you do to so is misinformed. Make sure it is still zeroed from the travel and hunt on.

Adjust your home range confirmed DA hit inputs to the current DA. If your first time shooting at a certain distance is on a hunt and at an animal, you are doing thing backwards.

I’m new to the calculator portion. I have a closed turret bdc scope that I used the calculator to match up bullet trajectories with and zero to the 3,4,5&600 yard crosshairs. I’ve been shooting out to 850 yards on 7x10 targets with it and not having to adjust anything. I don’t plan on shooting past 600 yards and my groups have been right at 3/4moa at 5&600. I guess I was just trying to take the easy route and see if there was a quick way to adjust the zero to accommodate the higher bullet trajectory for the bdc scope.

 

[Megalodon]

Gooooootcha. Sorry. That’s the info that makes this thread make sense. It’s also the reason lots of people recommend against BDC reticles or turrets.

What scope are you running? You should be able to find info online that will tell you the actual mil or moa measurement on that reticle, not just the yardage. I personally would zero at 100, then find the drop at elevation and line that up to the reticle.

Ex.
You find online that the 300 line is 1.3 mil from the center, 400 line is 2.1, 500 is 2.9 etc.

Punch in 9000’, the rest of your assumed hunting environmentals and ballistics. And find what lines up with your reticle. In this example what yardage with the assumed environs give you 1.3 elevation, say it’s 330 yards. Now that line on the reticle
Is your 330 line. Do that for each.

Not perfect but what I would do.

 

[Megalodon]

Or you could just call it good enough as is. Hold a little high and within 500 yards it probably won’t make a difference.

 

[KClark91]

Gooooootcha. Sorry. That’s the info that makes this thread make sense. It’s also the reason lots of people recommend against BDC reticles or turrets.

What scope are you running? You should be able to find info online that will tell you the actual mil or moa measurement on that reticle, not just the yardage. I personally would zero at 100, then find the drop at elevation and line that up to the reticle.

Ex.
You find online that the 300 line is 1.3 mil from the center, 400 line is 2.1, 500 is 2.9 etc.

Punch in 9000’, the rest of your assumed hunting environmentals and ballistics. And find what lines up with your reticle. In this example what yardage with the assumed environs give you 1.3 elevation, say it’s 330 yards. Now that line on the reticle
Is your 330 line. Do that for each.

Not perfect but what I would do.

Yea I purchased the scope years ago, before I planned on really shooting further than 400. That’s pretty much what I did. I found the scope specs for the bdc crosshairs and then found what zero I needed with the ballistic calculator for the ammo I’m using to match up the 3,4,5&600 yard marks to the trajectories. If I take my 1.5 high zero at 0 elevation and adjust it to 1.0 high at 9k elevation the trajectories are within an inch on the ballistics calculator . I was just wondering if I was doing it right or how accurate it would be if I just dropped my zero .5 moa to match the trajectories for the higher elevation.

 

[EdP]

Run your ballistic calculator at 2000' to determine how high a 200 yd zero will be at 100 yds and sight in for that. Verify the holdovers out to your max distance at the range at 2000ft. Run your ballistic calculator for your hunt location and atmospherics using your 200 yd zero and go hunt using the calculated holds for your hunt location. Verify your 100yd sight in after arrival if you like. Your hunt location hold overs or dials will be a bit different but should be good.

This has worked for me out to 500 yds and I would not hesitate to use it out another 100 or 200 yds. It may be fine out further but I will leave that to those with experience in those more distant realms.