Page 1 of 3 123 LastLast
Results 1 to 20 of 41

Thread: Shooting up/down hill

  1. #1
    Member
    Join Date
    Feb 2009
    Location
    Anchorage
    Posts
    206

    Default Shooting up/down hill

    Got a question about shooting either up or down hill. I seem to remember reading something years ago about this, but don't remember the specifics. I understand the whole horizontal distance vs. the distance up or down slope, but I'm still confused. If I'm sighted in at about 2 1/2 inches high at 100 yards, and the horizontal distance is under 200 yards, shouldn't I just hold on-target and still be within my margin of error? Any and all help appreciated- thanks!

  2. #2
    Member Frostbitten's Avatar
    Join Date
    Jun 2010
    Location
    Alaska - I wasn't born here, but I got here as soon as I could!
    Posts
    3,279

    Default

    Quote Originally Posted by ANCguy View Post
    Got a question about shooting either up or down hill. I seem to remember reading something years ago about this, but don't remember the specifics. I understand the whole horizontal distance vs. the distance up or down slope, but I'm still confused. If I'm sighted in at about 2 1/2 inches high at 100 yards, and the horizontal distance is under 200 yards, shouldn't I just hold on-target and still be within my margin of error? Any and all help appreciated- thanks!
    Depends on the severity of the angle. Personally, I would get too bogged down with trying to figure it out mathematically, find a place out in the field to practice.

  3. #3
    Member 1Cor15:19's Avatar
    Join Date
    May 2009
    Location
    Dillingham, AK
    Posts
    2,482

    Default

    Quote Originally Posted by ANCguy View Post
    Got a question about shooting either up or down hill. I seem to remember reading something years ago about this, but don't remember the specifics. I understand the whole horizontal distance vs. the distance up or down slope, but I'm still confused. If I'm sighted in at about 2 1/2 inches high at 100 yards, and the horizontal distance is under 200 yards, shouldn't I just hold on-target and still be within my margin of error? Any and all help appreciated- thanks!
    As Frostbitten suggests there are more variables than the zero at 100 yards, i.e. how large is the target, how high is the scope mounted in relation to the bore, the actual angle, etc. I normally disregard the angle except for all but the steepest or longest shots. Your shot will hit higher than the POA, whether of not it will be significant I can't say without more information.
    Foolishness is a moral category, not an intellectual one.

  4. #4
    Member gunbugs's Avatar
    Join Date
    Jul 2007
    Location
    Fairbanks
    Posts
    1,382

    Default

    Basically the answer to your question is yes. That is without getting into splitting atoms or rocket science. When shooting up or down a slope, the only thing to be concerned with is the distance to your target on a horizontal line. Think how far away are you if you were level with your target. That is the distance to correct for. Thats all the fancy laser rangefinders do for you, is compute the horizontal distance to the target.
    "A strong body makes the mind strong. As to the species of exercises, I advise the gun. While this gives moderate exercise to the body, it gives boldness, enterprise, and independence to the mind."

  5. #5
    Member Dan in Alaska's Avatar
    Join Date
    Feb 2007
    Location
    Anchorage
    Posts
    854

    Default

    Quote Originally Posted by ANCguy View Post
    If I'm sighted in at about 2 1/2 inches high at 100 yards, and the horizontal distance is under 200 yards, shouldn't I just hold on-target and still be within my margin of error?
    That should be well within minute-of-moose accuracy.

  6. #6

    Default

    Simple answer is aim low when shooting uphill or downhill.
    PROUD TO BE A VETERAN

  7. #7
    Member Eastwoods's Avatar
    Join Date
    Sep 2007
    Location
    Southern Tier, New York
    Posts
    430

    Default

    I agree. Mostly.

    Quick example. If we range 283 yards at a very sharp angle down hill or up hill (45 degrees for this example) and we didn't have a fancy range finder that calculates the horizontal line, we could get in trouble. The horizontal distance would only be 200 yards. For many of our rifles this would only cause an approximate 4" to7" high hit (assuming a 200 yard zero). Minute of moose? I would say so. But, for some of our not so flat shooting rifles it could mean a miss.

  8. #8
    Member Frostbitten's Avatar
    Join Date
    Jun 2010
    Location
    Alaska - I wasn't born here, but I got here as soon as I could!
    Posts
    3,279

    Default

    Quote Originally Posted by Eastwoods View Post
    I agree. Mostly.

    Quick example. If we range 283 yards at a very sharp angle down hill or up hill (45 degrees for this example) and we didn't have a fancy range finder that calculates the horizontal line, we could get in trouble. The horizontal distance would only be 200 yards. For many of our rifles this would only cause an approximate 4" to7" high hit (assuming a 200 yard zero). Minute of moose? I would say so. But, for some of our not so flat shooting rifles it could mean a miss.
    Also, think about this. When shooting flat and level, the reason the bullet drops over distance is because of gravity. Now, when shooting down at a sharp angle, does the velocity of the bullet over come the force of gravity and therefore, the impact is high? Seriously, I've never been able to get an answer to this question. If shooting straight down (90 degrees), it seems to me the bullet would continue along the vertical axis as the distance increases, so at lesser angle, the same should be true, up to a point. In my mind, that's at least partially the reason you have to aim low.

    Maybe someone can figure it out, but for me, it's too much math. Trigger time is the best way to figure this out.

  9. #9
    Member
    Join Date
    May 2008
    Posts
    6,031

    Default forget the math and keep it simple re: bullet drop uphill/downhill

    Quote Originally Posted by Frostbitten View Post
    ... it seems to me the bullet would continue along the vertical axis as the distance increases, so at lesser angle, the same should be true...

    Maybe someone can figure it out, but for me, it's too much math. Trigger time is the best way to figure this out.
    Math is not the easiest way to understand why shooting EITHER up or down, your bullet will have less drop. Here is the easy way:

    Imagine shooting straight up, perpendicular to the ground (nevermind how dumb that would be for a second). How much "drop", meaning how much below where where the barrel is pointed would the bullet actually go? The answer of course is zero. Zero drop.

    Next imagine being way up high and pointing your barrel directly downward and shooting. How much "drop", meaning how much below where the barrel is pointed would the bullet go? Again the answer of course is zero.

    So, Zero drop going EITHER straight up or straight down.

    Next its easy to imagine that the most drop you'll see is exactly between these two points, meaning when you point the barrel parallel with flat ground.

    So shooting level is your worst case of bullet drop, and everything else, either uphill or downhill, is less bullet drop.

    That make it any clearer? It did for me when I first heard that explanation.

  10. #10
    Member marshall's Avatar
    Join Date
    Nov 2007
    Location
    Near Phoenix, AZ
    Posts
    1,814

    Default

    We all know what approximately 30 degrees up or down looks like. If you have a fancy co-sign indicator it will give you a .89 factor. What that means is take your laser range and multiply it by .89 for an equivalent distance.

    I use 10% for easy math, 1.0 minus 10% is .90, that's close enough to .89 It's just fine for hunting accuracy where your kill zone is 10 inches. Shots work just the same up or down hill if your angle is between 25-35 degrees. Gravity acts straight down to the earth so up or down 30 degrees puts the bullet 60 degrees to horizontal, either way.

    A 500 yard shot minus 10% looks like this, 500-50 = 450 yards. If your shooting up or down hill around 30 degrees and your target is at 500 yards your shot will hit as if it was 450yards.

    Hope that helps...

  11. #11
    Member AKDoug's Avatar
    Join Date
    Apr 2006
    Location
    Talkeetna
    Posts
    5,714

    Default

    Marshall, good post. Unfortunately, most folks have no idea what 30deg actually looks like. 30 degrees puts you into the upper steepness range of many black diamond ski runs in this country. 30 degrees puts you on a 7/12 pitch roof that is very difficult to stand on depending on the roof surface. 30 degrees is where you need to start getting very concerned about avalanches in bad conditions.

    Even with a correcting range finder I limit my shots to right around 300 yards. With my 30-06 sighted in for 200 yards I am only 8" low at 300. For a moose I just hold center mass behind the front leg and I am going to hit vitals at any distance out to 300 yards. With smaller critters like sheep and deer it's a simple lay the horizontal cross hair on the back of the animal and I am well into the vitals. No mental games, no second guessing, and none of the hold high or low stuff.

    When I have coached people in archery I find that if I tell them to hold a little high or a little low they hit WAY high or WAY low. I now tell them to do the calculation and aim at a spot. Say the animal is at 35 yards and when you pull up your bow and the 30 pin is on it's back and the 40 is on it's belly. Aim where the 30 pin is hitting and keep aiming there. Whereas when I told them to aim a little high, or a little low they wouldn't take the time to look at the target and the "little" became "a lot". This sure seems like splitting hairs, but it has some strange mental effect on folks and it works.

    This is also one of the reasons I limit myself to 300 yard shots. Anything after that and I have to aim off the animal with the scope I use. I would have to go to one of those special reticles that allow me to hold at different distances, or a more target/sniper oriented scope that has external adjustments. 300 yards is far enough for me because I like what I use currently and a lot can happen when you get beyond that range.
    Bunny Boots and Bearcats: Utility Sled Mayhem

  12. #12
    Member Frostbitten's Avatar
    Join Date
    Jun 2010
    Location
    Alaska - I wasn't born here, but I got here as soon as I could!
    Posts
    3,279

    Default

    Quote Originally Posted by FamilyMan View Post
    Math is not the easiest way to understand why shooting EITHER up or down, your bullet will have less drop. Here is the easy way:

    Imagine shooting straight up, perpendicular to the ground (nevermind how dumb that would be for a second). How much "drop", meaning how much below where where the barrel is pointed would the bullet actually go? The answer of course is zero. Zero drop.

    Next imagine being way up high and pointing your barrel directly downward and shooting. How much "drop", meaning how much below where the barrel is pointed would the bullet go? Again the answer of course is zero.

    So, Zero drop going EITHER straight up or straight down.

    Next its easy to imagine that the most drop you'll see is exactly between these two points, meaning when you point the barrel parallel with flat ground.

    So shooting level is your worst case of bullet drop, and everything else, either uphill or downhill, is less bullet drop.

    That make it any clearer? It did for me when I first heard that explanation.
    Good point Familyman. I should have qualified my statement that I was assuming the use of a scoped rifle. When on flat and level ground, the scope/line of sight is also flat and level, but the barrel / trajectory isn't. Trajectory starts low (below the scope) then rises up the y axis for a finite distance, then begins to drop. If gravity is taken out of the equation, the bullet should continue along the y axis indefinitely.......ahhh screw it, this is hurting my brain, just aim low!

  13. #13
    Moderator LuJon's Avatar
    Join Date
    Mar 2007
    Location
    Palmer, AK
    Posts
    11,415

    Default

    I disagree.....

    I sight my rifle in for MPBR limiting it to 4" high to 4" low. It will shoot about 315 yards meeting this criteria. This means that all I have to do is hold center-o-mass out to 315 to hit the good stuff on any animal worth hauling out on my back. Doing it at an angle, either up or down, just increases that effective range. At 30* a dead on hold will net my setup a MPBR of 346 yards!! That is a plenty long poke and if I can't get within that range then I will keep hunting till I can.

  14. #14
    Member Smokey's Avatar
    Join Date
    Jul 2008
    Location
    Central Illinois
    Posts
    3,334

    Default

    Quote Originally Posted by AKDoug View Post
    Marshall, good post. Unfortunately, most folks have no idea what 30deg actually looks like. 30 degrees puts you into the upper steepness range of many black diamond ski runs in this country. 30 degrees puts you on a 7/12 pitch roof that is very difficult to stand on depending on the roof surface. 30 degrees is where you need to start getting very concerned about avalanches in bad conditions.

    Even with a correcting range finder I limit my shots to right around 300 yards. With my 30-06 sighted in for 200 yards I am only 8" low at 300. For a moose I just hold center mass behind the front leg and I am going to hit vitals at any distance out to 300 yards. With smaller critters like sheep and deer it's a simple lay the horizontal cross hair on the back of the animal and I am well into the vitals. No mental games, no second guessing, and none of the hold high or low stuff.

    When I have coached people in archery I find that if I tell them to hold a little high or a little low they hit WAY high or WAY low. I now tell them to do the calculation and aim at a spot. Say the animal is at 35 yards and when you pull up your bow and the 30 pin is on it's back and the 40 is on it's belly. Aim where the 30 pin is hitting and keep aiming there. Whereas when I told them to aim a little high, or a little low they wouldn't take the time to look at the target and the "little" became "a lot". This sure seems like splitting hairs, but it has some strange mental effect on folks and it works.

    This is also one of the reasons I limit myself to 300 yard shots. Anything after that and I have to aim off the animal with the scope I use. I would have to go to one of those special reticles that allow me to hold at different distances, or a more target/sniper oriented scope that has external adjustments. 300 yards is far enough for me because I like what I use currently and a lot can happen when you get beyond that range.
    Good stuff AKDoug, I feel the same way - very seldom have I had any need to shoot beyond 300 - actually seldom past 150yds. I have taken several coyotes out a ways but most were in pretty flat terrain. I can see sheep being a challenge though - along with steep angles there can be some bullet climb from sighting in at sea level then hunting at high elevations as well.... Since I honed my skills as a bowhunter getting closer for sure hit rifle shots has been much easier....
    Telling anyone to hold over a bit is pretty tricky as we all have different perceptions....
    When asked what state I live in I say "The State of Confusion", better known as IL....

  15. #15
    Member AKDoug's Avatar
    Join Date
    Apr 2006
    Location
    Talkeetna
    Posts
    5,714

    Default

    LuJon has a good point too. If you are comfortable using his method it's a good one, especially with the flatter shooting magnums vs. a 30-06 that I use. Chuck Hawks ( http://www.chuckhawks.com/rifle_trajectory_table.htm ) has a great table to roughly calculate your maximum point blank range and I've been seriously considering using this method vs. the one that has served me so well for all these years. I like Chuck's use of +/- 3" instead of Jon's 4"
    Bunny Boots and Bearcats: Utility Sled Mayhem

  16. #16
    Member
    Join Date
    May 2008
    Posts
    6,031

    Default too much adjustment to the aim point, and aim small = miss small

    Quote Originally Posted by AKDoug View Post
    When I have coached people in archery I find that if I tell them to hold a little high or a little low they hit WAY high or WAY low. I now tell them to do the calculation and aim at a spot.
    I find the exact same thing. "Hold a little low" and he clips their their darned toenails...

    "Aim at a spot" like you say Doug is some of the best advice I know. Or even more detailed, aim at a hair, miss by a hair. Actually visualizing which hair on the animal you're aiming at does work to improve accuracy I've found.

    That's better than a persons aim point being the side of the moose (and a subsequent miss by a distance of the size of a moose).

    I know these are generalizations, but I've found they can help train sons and daughters to be more accurate. My kids know that the words "gun control" is a good thing because it means hitting what you aim at.

  17. #17
    Supporting Member Amigo Will's Avatar
    Join Date
    Nov 2008
    Location
    Wrangell
    Posts
    7,600

    Default

    Quote Originally Posted by Water-Man View Post
    Simple answer is aim low when shooting uphill or downhill.
    Always shorter than a shot on the level. My goat was a hundred yards shot but being stright over my head looking over a rock it was point blank range
    Now left only to be a turd in the forrest and the circle will be complete.Use me as I have used you

  18. #18
    Member AKDoug's Avatar
    Join Date
    Apr 2006
    Location
    Talkeetna
    Posts
    5,714

    Default

    Case in point. When my son, 12 at the time, was confident on a long shot on a deer. I told him right where to hold and he only missed by about an inch of where I told him to hold and he had a dead deer. Had I told him to hold high I doubt he would have hit at all.
    Bunny Boots and Bearcats: Utility Sled Mayhem

  19. #19
    Member Smokey's Avatar
    Join Date
    Jul 2008
    Location
    Central Illinois
    Posts
    3,334

    Default

    I remember my son - age 10 - shotgun deer hunting for the first time. I mtd a scope on a 20ga youth 870 - first deer was a 6 point - came in to about 20 feet - I said aim low on the chest - he missed - deer ran out to about 75 yards and I said aim at middle - dead deer!
    At 20 feet the scope was on the low spot - trouble was the barrel was actually pointing under it!
    I think black bears have been the toughest for me to pick a spot when bow hunting - man under low light the shoulder and body just melt together!
    When asked what state I live in I say "The State of Confusion", better known as IL....

  20. #20
    Member marshall's Avatar
    Join Date
    Nov 2007
    Location
    Near Phoenix, AZ
    Posts
    1,814

    Default

    [QUOTE=AKDoug;811742]Marshall, good post. Unfortunately, most folks have no idea what 30deg actually looks like. 30 degrees puts you into the upper steepness range of many black diamond ski runs in this country. 30 degrees puts you on a 7/12 pitch roof that is very difficult to stand on depending on the roof surface. 30 degrees is where you need to start getting very concerned about avalanches in bad conditions.

    AKDOUG,

    I should have known that this would be one of those threads...

    I was trying to KIS, (Keep It Simple.) I know that 30 degrees is quite a slope. However it is probably worst case and even then it's only a 10% correction, that was my point. I assumed that an up or down hill shooter would be hunting sheep or goat, perhaps a mis conception.

    My step brother has 16 Rams to his belt as of this past August. Most were taken around 300 yards, some under 100 and 2 over 600, he shoots a 338WM. I just picked 500 yards as an easy number that would probably be the max range for most mountain hunters. Having said that, the windage is going to be a bigger issue for most.

    The angle I was refering to is the angle from the butt to the muzzle when the shooter is ready to fire not the climb to your target. Most of us would have a very diffecult time with a 30 degree slope, that's for sure. I imagine most would make the shot and find an easier way up or down to retrieve their prize.

    I was shooting my new 338LM this morning at 300 yards. The 200 yard line is higher than the 100 yard line and the 300 yard line is further up the hill than the 200 yard line. The co-sign angle was .98 so that's about 10 degrees. At that distance a 300 yard shot acts like 294, hardly worth messing with unless you're shooting groups at the bullseye.

    In a hunting situation as you well know the further the shot in most cases the less the angle and therfor less error from actual distance. Again in that situation reading the wind is a bigger concern. Only in the close shots at steep angles does the hold really change. However, at distances under 300 yards most guys can just hold on furr and hit the vitals.

Page 1 of 3 123 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •