Home Forums Hunting & Shooting Elk Hunting Effects of Altitude on My Bullet

I am going elk hunting this October in the Grants,NM/Mt.Taylor area. The altitude will be 6500-11000. Where I hunt in Va the altitude is only 400-500. Any idea of the effect the altitude will have on my bullet?

Shoot your rig when you get there. Adjust accordingly.

I will definitely shoot upon arrival. Was just curious what I could expect the bullet to be doing. ..high? Low?

For years I dialed in near sea level and hunted elk and mule deer out to 300 yards at ~12,000 feet and killed every thing I pulled the trigger on. This with a schitty non-temperature sensitive log powder. Must have been damn lucky...

The air is less dense so you'll be shooting with less drop at distance. Download a ballistics program to get the numbers. The difference for me between 5,000 feet and 10,000 feet, shooting a .308 with 168's is roughly 1 moa at 500 yards.

I have several young technical hunting buddies who cant help but worry about minutiae they see on TV. We sight in at 4000 ft and hunt at 8000-10000.


one of the guys used a software simulation to determine the difference - at 400 yards the difference in point of impact was .2" using 300 magnum ballistics. If you plan to shoot elk at 1000 yards you should factor that calculation into your shot.......for real world hunting not a big deal.
My best day on the bench has more wobble than elevation difference.

Assuming a 30-06 firing a 168 TTSX @ 2750fps mv, th difference between 950' ASL and 8950' ASL at a 600 yard target is 1.6 MOA or about 10 inches less drop. Windage will differ, too. Those numbers are assuming identical temperature and other variables. It's ip to you to run your specific numbers and determine if there is enough of an issue for you to worry about. If you're only shooting 300yards it's probably not going to matter.

Also, shooting at a severe angle up or down will make you bullet hit even higher!

With a bow, that can make a big difference. With a flat shooting bullet, the difference is very small.

No objective testing here, but I've noticed when checking a zero at a 6,500 - 7,000 foot elevation (after zeroing at a home altitude of a little over 600 feet), point of impact has been almost an inch higher at 100 yards. Windage virtually unchanged.

How much of this change can be attributed to an elevation difference or a cheap, worn-out rest system on the outfitter's range, I don't know.

Rifles have been chambered in .270 Win. and 7x61 Sharpe & Hart.

You can plug the numbers into most ballistics programs and get an idea. I doubt it is enough to matter until you get well past 300 yards. I use this, you'll have to click on the "advanced" version to factor in elevation.

http://www.hornady.com/ballistics-resource/ballistics-calculator

A bigger concern is how the effects of altitude, humidity, and temperature will have on a wood stock. I hunted there in 2010 with 5 other guys. We left Georgia at about 80 degrees, 500' elevation and 80% humidity. After 28 hours of driving we were in 30 degree weather, 7000' elevation and about 40% humidity. The 4 synthetic stocked rifles were still zeroed, the 2 wood stocked rifles needed adjustment.

I appreciate the information. I will be using a savage 300 win mag weather warrior with 165 gr interlocks. I love asking for advice here. Very knowledgeable. Greatly appreciated.

Air density is what effects the trajectory. As a general rule, the higher the elevation, the lower the air density. However, weather patterns change air pressure and thus air density, as does temperature. Buy a Kestrel weather instrument. It will provide "density altitude" and/or a true atmospheric pressure, which is the key to evaluating the real effect on the trajectory, and plug that into ballistic software. There are several which can be downloaded on a phone for $10 - $15.

Also, take a chronograph with you if you can. Velocity will change with the temperatures, the question is how much. Even the Hodgdon Extreme powders change somewhat with temperatures, just less than others.

Another factor to consider, shooting at angles, up or down, decrease the horizontal distance to the target, and thus, decrease the elevation correction required.


For long range shooting, all factors matter.

I shoot 180 grain in 300 win mag. I set my zero at 200 yards in Oklahoma.
I know from 15 years that at altitude I need to drop my turret 5 clicks (1.25 MOA) to keep my zero when I hunt over 10,000 feet.

I don't have any problems with my wood stock guns because I have floated the barrels. Solves that problem.

Shooting up hill or down can make somewhat of a difference. Lets say your gun is sighted in for dead on at 200 yards. That would mean it would be aprox 1 inch high at 150 yards.

Now lets say you are shooting at something 300 yards, but shooting at a 45 degree angle (not highly likely, but not out of the relm of possibility in the mountains). That means you would have to sight as if he was 150 yards instead of 300. But that bullet at 300 yards would be around 6-7 inches low (in most calibers). So, instead of holding 6-7 inches high, you would hold dead on for a 300 yard shot at a 45 degree angle.

Factor in the narrowed effective target and that can be a reason for a miss. If you are looking down at an animal, you don't have the full width of him to shoot at because on the angle, he is narrower.

Just one more thing to make your mind go crazy when the big-un steps out!

Going "up there," barometric pressure, temp, and humidity will probably vary significantly from your locale. This [/b]will[b] affect POI in different directions but don't get too deep in the weeds on this. Assuming you have a 200-yard zero now, recheck and confirm when you get to your hunting area and you should be good to 400 within a couple inches at those altitudes.

Assuming you are deer/elk hunting, you have a ten to fifteen inch target respectively.

I might add that as important or more so than potential POI changes is your adjustment to altitude. I'm assuming from your question that this might be a new or almost new endeavor for you. If you are driving you will gain some accommodation over a couple days as "you go up" though not a lot. Flying is another story, coming from about sea level as you are, to several thousand or more feet, driving to camp, and then being active--be careful. At the ski resorts this scenario amounts to several fatalities annually to otherwise healthy folks.

Acute mountain sickness can come on any time from 6k on up and looks and feels like the flu with headache, insomnia, sluggishness, etc. Drink a lot of fluids (your friend) and I would suggest an Aspirin or two every four hours for the duration. It can proceed to HACE (high altitude cerebral edema) or HAPE (high altitude pulmonary edema), both of which are very serious. You must get down hill fairly quickly.

Didn't mean to divert the subject but I've seen this happen in a ski resort and heard of it happening to elk hunters. There is a diuretic that can be used prophylacticaly but a friend I have found that the side effects were not worth it for us. Just a thumbnail description, but if you have any questions feel free to PM.

Now there is some good common sense hunting advice. Take your kestrel, Chronograph, ballistics calculator, certainly a tripod and sandbags, and maybe a Sherpa to help you carry all your crap up the hill.

Practice with your rifle, if you plan to shoot farther than 400 yards practice from field positions, not a gosh darn bench, a lot more than you think necessary. Then invest in a rifle scope with a reticle that makes the drops easier to shoot with confidence. I like the Zeiss Z600 but you can pick from a bunch. Adjust your zero to hit at 200 when you arrive at altitude and give your mind a break from this ballistic monkey spanking.

Windage estimation at ranges over 500 yards make clean kills unlikely with any amount of mountain wind blowing. The altitude and barometric pressure wont matter inside 400 yards. Use a rangefinder with angle calculation to save another headache.

The most high tech dedicated elk hunter i know who has killed bulls over 700 yards with his fancy 30-378 and all the special long range gear missed 4 times cross canyon just over 400 because of the wind.

Spend your extra time running stairs or hiking hills instead of worrying about ballistics -the results will be noticeably better.

What, you don't?

Special Needs,

What an interesting knot of contradictions you offer, without answering the OP's question. He asked a question for reasons that are important to him.

The nature of the question suggests limited experience with long range shooting, so it is good he has asked, and it would be even better to try to help him succeed.

His profile says he is from Fredericksburg, Virginia. So he is coming from sea level with high temps.

Going to 7,000'+ and temps that will be somewhere between 50 - 100 degrees colder will result in some very different trajectories for him from his home range.

Re-zeroing the rifle once on location is a good start, but only the beginning of making an accurate adjustment.

You suggest carrying a rangefinder and even one with an angle function; prudent suggestion to add that tool, or a cosine indicator on the rifle will work also if he does not wish to buy a new rangefinder.

Once he has an angle or cosine reading, what is he supposed to do with it next?

Most folks are going to have a phone on them these days. Adding a ballistic app adds no weight, but does add knowledge, which ups the likelihood of making a good shot including windage and angle correction. Some are free and others are very modest in cost.

He can run some numbers at home, print it out, and stick it on the rifle, with some pretty close estimates of the environmental conditions.

A Kestrel weighs 2.3 ounces. As you correctly observe, wind is the biggest challenge and a Kestrel adds an objective metric to that variable. If an extra 2.3 ounces is a deal breaker, there are bigger challenges present and better resolved with your suggestion of hitting the stairs. A check during a slow time can provide information, which can be useful later if a shot needs to be made in a hurry.

Missing four times at 400 yards illustrates the value of actually having the ability to use some objective metrics coupled with actual understanding and practice rather than just a SWAG as your friend apparently did.

Guesses causes misses, as your friend demonstrated. Odd that he did not make a correction after the first miss, or second, or third.

Even with a Kestrel, winds can do strange things on slopes with valleys or rises in the middle. There is no substitute for practice, and on that we agree.

The chrony is not to lug up a mountain obviously, and he can leave it at home. It was just a suggestion if there is room and he is driving to remove another guess at another variable. His ammo will have slower velocity, how much will depend on the temp at which he worked up the load and the load itself. If he is using factory ammo, the info on the back of the box usually is just optimistic marketing hype with only vague correlation to reality and some factory fodder can have significant temperature sensitivity.

OP, as a fairly reliable alternative, find someplace near where you will hunt to take some practice at distances at which you expect to shoot. Actually confirming dope out to 500 or 600 yards out near where you will be hunting should produce accurate enough results. True statements are needed even with ballistic estimates.

Using a ranging reticle or a BDC turret will require correlation to actual conditions, the rifle, load, and some general environmental conditions. As long as there is some actual practice and correlation, they can work well. Personally, I prefer to dial elevation and hold wind, but that is just a general preference.

Anyway, good luck to all of you.