Calculating bullet trajectory when shooting up hill or down hill

[Brute 23]

Does any one on here know how to calculate your trajectory when shooting up hill or down hill? I've tried looking at several apps but they ask for factors I dont have or know.

Basically my scenario would be shotting from 50' high and low, out to 100, 200, and 300yds.

Next scenario would be 100' high and low, out to 100, 200, and 300yds.

I would be zeroed at 150yds with a 150gr, .308 bullet.

From what I'm reading your bullet impact should be higher than where you are aiming both high and low. It also said at less than 300 yds with a 30 deg angle you should be no more than 3" off at 300yds. I'm not sure what my angle is on those but 3" is a little loose for me.

My range finder doesnt calculate angle for me.

 

[Caustic Burno]

From Winchester

If you prefer to go old school, use the following widely utilized calculations upon determining the angle of your shot:

5 Degrees: Drop Inches x .004

10 Degrees: Drop Inches x .015

15 Degrees: Drop Inches x .034

20 Degrees: Drop Inches x .060

25 Degrees: Drop Inches x .094

30 Degrees: Drop Inches x .134

35 Degrees: Drop Inches x .181

40 Degrees: Drop Inches x .235

45 Degrees: Drop Inches x .293

50 Degrees: Drop Inches x .357

55 Degrees: Drop Inches x .426

60 Degrees: Drop Inches x .500

 

[callmefence]

Lots here more into this kinda thing than me.
But my two cents is range is determined by the distance the bullet is affected by gravity. So range would be the intersection of a line plum up or down from Target to a line level from the muzzle. Not a line directly from muzzle to Target.....that's all I got and I'm open to correction.

 

[Brute 23]

Ya I read that article and it was helpful. If I understand correctly the more you shoot down or up will give you the most angle and the most deviation with elevation. If your 100' up and your line of sight is 100 yds the deviation factor due to elevation is greater than being 100' up and shooting 300 yds, but when you factor the distance in also it start bringing them closer together. When looking at the charts like you posted it appears the degree of angle is calculated from the target at a level surface, to your muzzle. I know the apps want you to sit the phone on your barrel as you point it at the target so they can get that angle.

I think the part I'm missing is how to calculate that degree of angle. That's one of those sine/ cosine deals that is out of my realm. If I'm 100' up, line of sight is 200yds to target (hypotenuse), I think one of those formulas will tell you the degree of angle I need to use the chart you posted.

 

[callmefence]

Ya I read that article and it was helpful. If I understand correctly the more you shoot down or up will give you the most angle and the most deviation with elevation. If your 100' up and your line of sight is 100 yds the deviation factor due to elevation is greater than being 100' up and shooting 300 yds, but when you factor the distance in also it start bringing them closer together. When looking at the charts like you posted it appears the degree of angle is calculated from the target at a level surface, to your muzzle. I know the apps want you to sit the phone on your barrel as you point it at the target so they can get that angle.

I think the part I'm missing is how to calculate that degree of angle. That's one of those sine/ cosine deals that is out of my realm. If I'm 100' up, line of sight is 200yds to target (hypotenuse), I think one of those formulas will tell you the degree of angle I need to use the chart you posted.

Just shoot in there amongst em......

 

[Nesikep]

I can't offer anything on specifics, but when I'm shooting, I use some of the theory.. if you're shooting straight up or straight down, the only thing that's affecting the difference between where you're aiming and where you hit is how the gun is sighted.. bullet drop no longer matters because that's not in the same plane ... so height the scope is above the barrel and the sighting yardage is what makes the most difference.. Assuming you don't have much bullet drop at your sighting distance, if you're shooting vertically, at twice the sighting distance you're going to have to aim low by about the distance your scope is over the muzzle

 

[jltrent]

A lot of good info here. For me usually even with a bi-pod if I get over 100 yards I don't have the steadiness to be very dead on accurate.

 

[Dave]

I never worry about it. Just hold the middle of the chest right behind the front shoulder and touch it off. A hundred feet of difference on a 200 yard shot is pretty much flat ground around here. Shooting down hill hold higher. Not because of bullet trajectory but because of the bullet path through the animal. I have seen both deer and elk where the entrance hold looks real good but do to the steep angle the bullet went below the vital organs. I would imagine the same thing could happen on a up hill shot. With the bullet passing over the vitals. I just can't remember taking a steep up hill shot. I always hunt so I am up hill of the animals.

 

[SmokinM]

There are a couple of ways to calculate angles but for something like this I would probably keep it simple as a rise/run calculation. A 12/12 pitch is a 45 deg.angle. Figure your pitch and get your angle as a percentage from there or cheat and use a speed sq.

Should be a bunch of DOPE charts on .308 out there

 

[Brute 23]

There are a couple of ways to calculate angles but for something like this I would probably keep it simple as a rise/run calculation. A 12/12 pitch is a 45 deg.angle. Figure your pitch and get your angle as a percentage from there or cheat and use a speed sq.

Should be a bunch of DOPE charts on .308 out there

Thanks. That's my speed for calculating an angle. Never thought about it like that.

 

[Brute 23]

I've always been pretty particular about my shooting. I like them to drop right there... mainly because I'm lazy. At home you may be crawling on hands and knees to find one thru some nasty brush. The place I'm wanting to know about the elevation it may be in a draw or across a canyon or some thing if it runs and I darn sure dont want to pack a deer out of a canyon.

I grew up doing kneck shots per my dads rules. Then I shot a couple behind the shoulder because the places I went required it. Now I'm to the high shoulder and that's where I'm staying.