[sr20sean]

I got invited by my dad's cousin to go out to Montana with him to go hunting in a few months. I was told that most game would not be on the same elevation as us so I'm trying to understand how to tell how I should compensate for that. I was never taught how to gauge for elevation changes. Is there a formula? I figure it would be good to know for the future as well since I highly doubt all of my targets will be completely level from where I am shooting from.

Just some background on my dad's cousin: his father used to have an international dealers license before he passed away(he had a lot of money). Now he has all of the firearms that his father owned. (including all of the full auto ones and no he doesn't live in new york lol). His idea of a hunting rifle is a Barrett .50bmg or anything in .338 lapua and his idea of game is anything that he can see in his scope. So after knowing that I expect to hear from him "shoot that (elk/deer/moose/whatever Montana has) out there" even though it would probably be about a mile away. I've heard stories about him being upstate NY on a mountain shot a 12pt deer on another mountain, walked 2.5 hours with his gear down one mountain, across the valley, and halfway up the other one then decided not to keep it so he gave it to another hunter then he left.

But really I just want to know how to gauge where to aim for elevation changes. I know the center of the crosshairs at a level target would not be the same as the center of a target at a 10-15 degree level up or down since a downward angle would make it have a higher impact and an upward angle would make the bullet hit low.

 

[Guest]

1. What caliber, bullet and muzzle velocity will you be using?

2. At what elevation will you zero your rifle?

3. At what distance will you zero your rifle?

4. At what elevations will you be hunting?

With the answers to these questions you can derive firing solutions for various elevations under standard conditions.
Keep in mind that there will be variations due to changes in barometric pressure.

Or just don't shoot past 300-yards and you should be fine.

 

[Jeff]

So after knowing that I expect to hear from him "shoot that (elk/deer/moose/whatever Montana has) out there" even though it would probably be about a mile away.

If you have to ask the question you're asking here you don't have the skill to shoot a living thing at long distances and do it humanely. Targets are one thing but don't wound an animal because you're outside of your skill level.

 

[sr20sean]

1. What caliber, bullet and muzzle velocity will you be using?

This is where I'm not entirely sure. When I shoot I usually have my log book with the info on the round(charge, OAL, bullet weight), muzzle velocity, elevation, and where they hit. I don't do this with .22lr though since I only use bulk ammo. I also change out books between .223/5.56, .243, and .308 because I don't want them to get mixed up.

2. At what elevation will you zero your rifle?

All of mine are zeroed at approx 500'. I know most of Montana is around 2500'-3000' and I have no idea what the elevation levels where he lives in Maryland is, so I would imagine he would have to zero the rifles out there.

3. At what distance will you zero your rifle?

Mine are all at 100 yards. His probably will be at 300 yards if he brings the rifles I would imagine he is.

4. At what elevations will you be hunting?

probably 3000'-4000' unless for some unknown reason he decides that he wants to go into the higher elevations of the mountains.

With the answers to these questions you can derive firing solutions for various elevations under standard conditions.
Keep in mind that there will be variations due to changes in barometric pressure.

Or just don't shoot past 300-yards and you should be fine.[/QUOTE]

If you have to ask the question you're asking here you don't have the skill to shoot a living thing at long distances and do it humanely. Targets are one thing but don't wound an animal because you're outside of your skill level.

I agree. I wouldn't feel comfortable doing that since I know that sort of range is out of my skill level right now. This isn't going to be until mid fall so I figured I had some time to get practice. I have never had a problem with a .308 at 800 yards up near Middleburgh but that's shooting a target at a known distance/elevation and figuring out everything in my head/on paper. I don't own a ballistics computer or a rangefinder mainly because I can't afford either. My method of range finding is using one of those measuring wheels and adding up each time it rolls over back to 0 then dividing by 3 lol. Then get a general estimate of where my sights should be based on the data I have, then go from there. If I was hunting up in Middleburgh I'd have no problem with it since I'd know the terrain and pretty much have everything logged for that area.

And while typing this I got an email from him, after I had asked about ballistics computers and rangefinders, saying that he has the Barrett BORS on a Nightforce NXS 8-32x56 on three rifles. And one on another just with a Leupold mark 4 which I guess takes all the mathematical work away. (I really need to get into the oil industry it seems) and we would probably be taking the .338's out there since they are lighter if we needed to hike.

 

[wizrd]

You are wrong in your assumption, in the scenarios you describe, that one shot would go high, and the other would go low. Both shots, if the elevation is steep enough to affect them, would be high. Picture yourself on a high cliff, down below you & your rifle, say vertically below you, 900 yards along the line of sight, is your target. (Or this whole scenario could be YOU at the bottom, shooting UP, towards the cliff). Say your target is only standing 300 yards from the base of the cliff you are on, but the distance down or up the mountain is 900 yards. The gravity affecting the bullet drop, in this case, will only affect the bullet drop for the 300 yards that the bullet is actually travelling from your muzzle LINEARLY. I doubt you will have to worry about this, but for extreme distance shooting at extreme angles, it does need to be considered.

 

[Guest]

You are wrong in your assumption, in the scenarios you describe, that one shot would go high, and the other would go low. Both shots, if the elevation is steep enough to affect them, would be high. Picture yourself on a high cliff, down below you & your rifle, say vertically below you, 900 yards along the line of sight, is your target. (Or this whole scenario could be YOU at the bottom, shooting UP, towards the cliff). Say your target is only standing 300 yards from the base of the cliff you are on, but the distance down or up the mountain is 900 yards. The gravity affecting the bullet drop, in this case, will only affect the bullet drop for the 300 yards that the bullet is actually travelling from your muzzle LINEARLY. I doubt you will have to worry about this, but for extreme distance shooting at extreme angles, it does need to be considered.

You're confused. The post is about ballistics at higher elevations not taking sloped shots.

 

[Guest]

Example for a .308 @2,650 fps

Sea Level........................... 6,000' ASL
100-yards = 0 0
150-yards = +0.75 moa +0.75 moa
200-yards = +2.00 moa +2.00 moa
250-yards = +3.25 moa +3.00 moa
300-yards = +4.75 moa +4.50 moa

Inside 300-yards the variation due to elevation change (reduced air density) is small.

 

[meketrefe]

Many different ballistics software will give you a pretty accurate drop/windage trajectory.

Hornady, NF, nikon, Federal and many other websites have a simple calculating modules but this is not substitute for a comprehensive ballistic software that can be found for most operating systems for laptops, PDAs and smartphones.

You need all the above mentioned variables and a few more to make an accurate prediction. Bring a kestrel with you. Also the actual precise speed measured with the chrono in the same rifle is a must and this must be verified in the field before going to a LR hunt. The biggest challenge will be the wind calls. Consistency and repetatilbility are the things that we need to gain confidence and they can only be achieved by testing that 'math' in similar field conditions with the same rifle and your well known ammo. And even if we think we can take the shot it doesn't mean we should take that LR shot on a game. When confident but still in a little doubt if you are going to miss, then miss a bit high otherwise the debris might scare the animal and will prevent you from a correction and a second shot.

I like to first find out what I want to shoot, how far I can honestly and comfortably take the shot and if the round has enough horse power left to anchor that animal at that range and assure a swift humane kill. Otherwise move closer or just let it be. withing the 300-350 yards any flat shooting cartridge will present you with a pretty safe range to holdover at changing altitudes.

Cheers.

 

[sr20sean]

You're confused. The post is about ballistics at higher elevations not taking sloped shots.

I was actually talking about both but I figured out the sloped shot problem.

Example for a .308 @2,650 fps

Sea Level........................... 6,000' ASL
100-yards = 0 0
150-yards = +0.75 moa +0.75 moa
200-yards = +2.00 moa +2.00 moa
250-yards = +3.25 moa +3.00 moa
300-yards = +4.75 moa +4.50 moa

Inside 300-yards the variation due to elevation change (reduced air density) is small.

What program do you use for this?

Many different ballistics software will give you a pretty accurate drop/windage trajectory.

Hornady, NF, nikon, Federal and many other websites have a simple calculating modules but this is not substitute for a comprehensive ballistic software that can be found for most operating systems for laptops, PDAs and smartphones.

You need all the above mentioned variables and a few more to make an accurate prediction. Bring a kestrel with you. Also the actual precise speed measured with the chrono in the same rifle is a must and this must be verified in the field before going to a LR hunt. The biggest challenge will be the wind calls. Consistency and repetatilbility are the things that we need to gain confidence and they can only be achieved by testing that 'math' in similar field conditions with the same rifle and your well known ammo. And even if we think we can take the shot it doesn't mean we should take that LR shot on a game. When confident but still in a little doubt if you are going to miss, then miss a bit high otherwise the debris might scare the animal and will prevent you from a correction and a second shot.

I like to first find out what I want to shoot, how far I can honestly and comfortably take the shot and if the round has enough horse power left to anchor that animal at that range and assure a swift humane kill. Otherwise move closer or just let it be. withing the 300-350 yards any flat shooting cartridge will present you with a pretty safe range to holdover at changing altitudes.

Cheers.

I originally only took the opportunity because I wanted to get some long range shooting practice and use a few rifle I know I will never be able to afford haha. I may take my rifle out though to hunt just so I have something to feel comfortable with and something I would know the abilities of.