For those of you that have experience in the field making uphill/downhill shots what method do you use to calculate slant angle.
I'm trying to figure out what would be a good device to measure angles on uphill/downhill shots so that I can get the correct horizontal range to make an accurate shot.
Thanks people,
Aaron
Last edited by Aaronb2245; 06-03-2008 at 02:07 PM.
Reason: misspelled word
Here's what I understand taken from "The Modern Rifle" by Jim Carmichael published in 1975 and I see the going price is $107.00 used on Amazon.com (Haaaaaaaa...I have a copy) the angle up or down causes less gravity to pull the bullet downward. If you had an animal say 400 yards above you or below you (it doesn't matter) at 45 degees you will not need to hold as high over the back.
If no one can give you a formula the next few days on this post I'll see what I can find in the book. You might have to private mail me since this darn forum is just too big anymore to keep track of all the posts.
It is called an Angle Cosine Indicator. You multiply the cosine (cosine of 92 should read .92) by the yardage and get the corrected for gravity yardage to target. You make your adjustments based on the corrected for gravity yardage, but do not neglect the actual yardage when considering flight time on long shots.
In the old days they used a protractor, string and a paper clip to find the angle and then calculate the cosine, but it wasn't nearly as accurate...
For example, you are preparing to fire at a target 600 yards out. You cosine is .86 (fairly steep angle). You would multiply .86 X 600. Your corrected for gravity yardage to target would be 516 yards. Make your adjustments just like you were engaging a target at 516 (with exception of flight time) and you will be fine.
People thank you all for the help. I know how to do the math and understand all of the ballistics. I'm trying to make sure that when I do the math the angle I'm using is correct.
What I mean is if I think it's a 45 degree and and it's actually a 55 degree angle at decent distances this will be the difference between a hit and a miss. I simply would like to know what devices are available to let me know the exact angle.
For instance if I were making a 600 yards uphill shot at a 45 degree angle I would take the cosin of 45 (.71) and multiply it my 600yards to get the horizontal distance (426 yds) . However if I guessed the angle wrong and say it's 55 degree angle (cosin .57) and I needed to range for 342 yards rather than 426...well I'd obviously be shooting to high.
Thank you for replying this is what I am looking for a piece of gear .....more input would definately be appreciate from other ppl on some other devices so I can choose which one will work best for me.
Here's what I understand taken from "The Modern Rifle" by Jim Carmichael published in 1975 and I see the going price is $107.00 used on Amazon.com (Haaaaaaaa...I have a copy) the angle up or down causes less gravity to pull the bullet downward. If you had an animal say 400 yards above you or below you (it doesn't matter) at 45 degees you will not need to hold as high over the back.
If no one can give you a formula the next few days on this post I'll see what I can find in the book. You might have to private mail me since this darn forum is just too big anymore to keep track of all the posts.
Wow that book is quite expensive! I like "Understanding Firearom Ballistics" by Robert A Rinker the most up to date version is the 6th edition I got it roughly for 25 bucks and it's packed with all the info you could need. (why O WHY did I ever throw away my USMC scout sniper pubs?...I served)
Last edited by Aaronb2245; 06-04-2008 at 02:25 PM.
Reason: Automerged Doublepost
Where do you place it jimkim when you're out in the middle of no where and there's only trees,hills and dirt around? It also looks too big too put on the barrel. lol
And it has to be level in order to get an accurate reading doesn't it?
There's a few range finders out on the market now, Leupold being the first to offer it, that includes angle trajectory also. Can't say how well they/it works and I'm sure they're on the pricey side.
__________________ "My next door neighbors two dogs have created more shovel ready jobs then Obama has." - Gary Johnson
you want a cosine angle finder. there are a few on the market that attatch directly to your scope, or mounts.
This sounds perfect!! I will google for it!
Thank you very much,
Aaron
Quote:
Originally Posted by GlockMeister
Where do you place it jimkim when you're out in the middle of no where and there's only trees,hills and dirt around? It also looks too big too put on the barrel. lol
And it has to be level in order to get an accurate reading doesn't it?
There's a few range finders out on the market now, Leupold being the first to offer it, that includes angle trajectory also. Can't say how well they/it works and I'm sure they're on the pricey side.
I had wondered if newer laser range finders included that feature....I'm not into spending that much money on such a device at the moment.
Thank a lot for the input!!
Last edited by Aaronb2245; 06-04-2008 at 05:09 PM.
Reason: Automerged Doublepost
It is called an Angle Cosine Indicator. You multiply the cosine (cosine of 92 should read .92) by the yardage and get the corrected for gravity yardage to target. You make your adjustments based on the corrected for gravity yardage, but do not neglect the actual yardage when considering flight time on long shots.
In the old days they used a protractor, string and a paper clip to find the angle and then calculate the cosine, but it wasn't nearly as accurate...
For example, you are preparing to fire at a target 600 yards out. You cosine is .86 (fairly steep angle). You would multiply .86 X 600. Your corrected for gravity yardage to target would be 516 yards. Make your adjustments just like you were engaging a target at 516 (with exception of flight time) and you will be fine.
Are my posts invisible?!?!?! I even provided a link to buy one...
Are my posts invisible?!?!?! I even provided a link to buy one...
LOL I'm sorry I didn't see your post. Thank you *very much* for the link I'm going there now!!
After looking the device I have decided this is EXACTLY what I'm looking for, and on the same site I fund a product (mildot master) that can be used in conjunction to determine distance quickly using a mil dot scope among performing other calculations. It can also be used to determine the angle, however the cosine angle indicator is more efficient for this purpose. Using these 2 tools together will provide the shooter with quick adjustments and accurate information. Thanks a a WHOLE BUNCH for this link. This is exactly what I was looking for and more! I can't wait to test this gear out!!
Aaron
Last edited by Aaronb2245; 06-04-2008 at 10:52 PM.
Reason: added information
Kinda pricey, but you will not be disappointed, especially if you shoot a lot of uphill/downhill shots. I do not know what distance you will be shooting at but again, PLEASE remember flight time remains the same on long shots.
Yeah, I missed the joke. I thought he just "eyeballed it" for a distance and then measured and multiplied it to get his answer. Sounds kinda dumb when I write it out...
Where do you place it jimkim when you're out in the middle of no where and there's only trees,hills and dirt around? It also looks too big too put on the barrel. lol
And it has to be level in order to get an accurate reading doesn't it?
There's a few range finders out on the market now, Leupold being the first to offer it, that includes angle trajectory also. Can't say how well they/it works and I'm sure they're on the pricey side.
I only intended to help if at all possible. I had never used it like this before. I decided to try it. I took mine and placed it on the barrel of my 336. The magnet held. I was able to read the gage. Mine is like this one. It fits in my jacket pocket. I know it isn't built for firearms but it worked. Great NeckŪ 10155 Small Angle Finder - ToolKing.com
__________________
For info purposes only, use it at your own risk. JFKimmons and G&G aren't liable for it's misuse.
Last edited by jimkim; 06-05-2008 at 10:00 AM.
Reason: double post
I always string a string to the target and another horizontally level and meisure the difference in length. sam.
Um....that has to be a joke. That makes absolutely no sense what so ever mathematically and in logic. lol
Quote:
Originally Posted by jimkim
I only intended to help if at all possible. I had never used it like this before. I decided to try it. I took mine and placed it on the barrel of my 336. The magnet held. I was able to read the gage. Mine is like this one. It fits in my jacket pocket. I know it isn't built for firearms but it worked. Great NeckŪ 10155 Small Angle Finder - ToolKing.com
Even though that wasn't exactly what I was looking for I did appreciate your input!
Quote:
Originally Posted by billy
sure!
i do too.
doesnt everyone?
i never go anywhere without at least 500 feet of string.
ROFL.....
Last edited by Aaronb2245; 06-05-2008 at 01:03 PM.
Reason: Automerged Doublepost
my USMC scout sniper pubs?...I served)
Thank you *very much* for the link I'm going there now!! 
