Range Report What change in moa can I expect?

[elmerdeer]

I have my drops tested out 1000 yards, I have a 330 yard zero and my drop in moa at 1000 yards is 20moa, elvation is 400 ft, temp 60 farenheit, and pressure I think was 29.38 in hg.
Now I am going hunting in Saskatchewan in the end of November, the Temp will probably be around 0 farenheit if were lucky, the elevation will be 1650 ft average, by how much will my drop be affected in moa? And what calculations do I need to do to get to correct my drops?
I am not sure what the baro pressure will be there? Or is that a standard that depends on altitude?
Thank you
Elmer

 

[azimutha]

Re: What change in moa can I expect?

Lower temperatures mean more air resistance.
Higher altitude means less resistance.
Barometric pressure lessens with altitude, but can vary with weather.

You could try running your numbers through a ballistics calculator, such as JBM (free online). Do you know your muzzle velocity and the BC (ballistics coefficient) of the bullet? If not, that could be loosely extrapolated from your drop data. But I'm only mentioning all this to give you an idea that if you haven't already incorporated all this data into figuring your drop tables and don't have access at the time to immediate temperature and barometric station pressure readings, it won't be reliable (or ethical) to take shots out past your zero.

The alternative (and recommended anyway, esp. if flying) is to re-check your zero when you get there. If possible, maybe you can get out to an extended range. I'd check with someone up there beforehand.

 

[elmerdeer]

Re: What change in moa can I expect?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: azimutha</div><div class="ubbcode-body">Lower temperatures mean more air resistance.
Higher altitude means less resistance.
Barometric pressure lessens with altitude, but can vary with weather.

You could try running your numbers through a ballistics calculator, such as JBM (free online). Do you know your muzzle velocity and the BC (ballistics coefficient) of the bullet? If not, that could be loosely extrapolated from your drop data. But I'm only mentioning all this to give you an idea that if you haven't already incorporated all this data into figuring your drop tables and don't have access at the time to immediate temperature and barometric station pressure readings, it won't be reliable (or ethical) to take shots out past your zero.

The alternative (and recommended anyway, esp. if flying) is to re-check your zero when you get there. If possible, maybe you can get out to an extended range. I'd check with someone up there beforehand.</div></div>
My avg speed is 2950 avg, I am shooting a 180gr berger hybrid, bc for that bullet is .345 g7, I have been shooting to 1000yards and the gun is accurate and the drops are accurate, I will not take a shot that far if conditions are not perfect.
Thanks
elmer

 

[azimutha]

Re: What change in moa can I expect?

I'm assuming you are shooting a 7mm then...only Berger I see that's 180 gr. is in that size (http://www.bergerbullets.com/Products/All%20Bullets.html). The G7 BC is a bit lower shown there and I checked my copied of Applied Ballistics to confirm that. You'd really want to use that number in a ballistics calculator.

It's great that you have established real world data for your drops. If you have an opportunity to get back to the range and can somehow obtain barometric pressure, altitude, temperature and humidity (ideally with measuring equipment in hand, e.g. Kestrel or GPS; otherwise from the nearest airport - which would be okay if it's close and near the same altitude) that will give you good inputs for conditions when you established your zero.

Then you can enter that into JBM and at least do some estimating for the conditions you may encounter in Sask. I'd only feel right about taking a shot out past 400 if I had a handheld with a ballistics calculator, e.g. Shooter for Android devices or Ballistic on an iPhone/Touch and current, localized weather conditions/altitude. At least there's not much altitude variation there.

 

[elmerdeer]

Re: What change in moa can I expect?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: azimutha</div><div class="ubbcode-body">I'm assuming you are shooting a 7mm then...only Berger I see that's 180 gr. is in that size (http://www.bergerbullets.com/Products/All%20Bullets.html). The G7 BC is a bit lower shown there and I checked my copied of Applied Ballistics to confirm that. You'd really want to use that number in a ballistics calculator.

It's great that you have established real world data for your drops. If you have an opportunity to get back to the range and can somehow obtain barometric pressure, altitude, temperature and humidity (ideally with measuring equipment in hand, e.g. Kestrel or GPS; otherwise from the nearest airport - which would be okay if it's close and near the same altitude) that will give you good inputs for conditions when you established your zero.

Then you can enter that into JBM and at least do some estimating for the conditions you may encounter in Sask. I'd only feel right about taking a shot out past 400 if I had a handheld with a ballistics calculator, e.g. Shooter for Android devices or Ballistic on an iPhone/Touch and current, localized weather conditions/altitude. At least there's not much altitude variation there.</div></div>
I be at the range again soon, before I head out to sask and will recheck everythin.
The bullet is a new offering from Berger and it has the G7 BC of all ther 180 gr bullets it is .345.
I am now looking for a ballictic program for a hanheld any suggestions?
And thanks for the input.
Elmer

 

[ubet]

Re: What change in moa can I expect?

Shooter is a good program, simple quick and easy to use. You have to have a phone with android os on it though. If you have a kestrel, you dont even need service for the app to work.

 

[Greg Langelius *]

Re: What change in moa can I expect?

All of these recommendations are good. Given the data you have and the data you expect, some fairly good estimates can be determined.

However, they are just that, estimates. They can put you in the ballpark, but on the dot? Dubious, honestly.

I'm not a big proponent of long range hunting, and this dialogue illustrates why I am that way. A hunter comes from one set of circumstances, to a place with a whole new set of circumstances, then seeks out a shot which would be marginal under any circumstances. You can only change so any parts of the equation before it starts becoming garbage in, garbage out.

On assumes this is a much anticipated hunt with much preparation and a fairly upthere pricetag. My suggestion is to pack a little insurance, in the form of a relatively conservative approach to which shots you attempt.

Greg

 

[former naval person]

Re: What change in moa can I expect?

I agree with Greg. If you blow your one chance at a nice trophy at 700 plus yards when you could stalk to within 250-300 yards...awfully costly ego trip. JMHO

 

[AKAce]

Re: What change in moa can I expect?

Thousands of Deer are shot every year @ 25 - 75 yards with Piss Poor Hits...

Long Range hunting is "Generally" done by advanced shooters, with better equipment. A Miss is still a Miss, be it 75 yards or 750, a bad hit is still a Bad hit...

With normal LRH Calibers, a Good hit puts them down just as fast as Good short range hits.

I fail to see ANY dif in the 2, morally, Ethically, or for any other reason. Miss is Miss, Dead is Dead, gut shot is Gut Shot.

If you feel good about making the shot, and your bullet has the horsepower to get the job done on arrival.... Post the pics of your Trophy !

 

[elmerdeer]

Re: What change in moa can I expect?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ~Ace~</div><div class="ubbcode-body">Thousands of Deer are shot every year @ 25 - 75 yards with Piss Poor Hits...

Long Range hunting is "Generally" done by advanced shooters, with better equipment. A Miss is still a Miss, be it 75 yards or 750, a bad hit is still a Bad hit...

With normal LRH Calibers, a Good hit puts them down just as fast as Good short range hits.

I fail to see ANY dif in the 2, morally, Ethically, or for any other reason. Miss is Miss, Dead is Dead, gut shot is Gut Shot.

If you feel good about making the shot, and your bullet has the horsepower to get the job done on arrival.... Post the pics of your Trophy ! </div></div>
Thank you for your support Ace. The only shot I will take is a good one if I have a doubt I will not squeeze the trigger, whether its 10 yards or 600 yards, unlike someone I know who last year injured 2 deer 1 was at 10 yards and the other was 50 yards and both animals were not recovered! As for me I took two deer last year at 475 yards and did not have to track anything! Practice is always a eye opener on what your capable of, my gun shoots well out 1000 yards, doesnt mean I will shoot at animal that far but its always good to know that you can if everything is perfect.
Elmer