Go Back   Maryland Shooters > Topics of Interest > Outdoor Sports
Don't Have An Account? Register Here

Closed Thread
 
Thread Tools Display Modes
Old November 20th, 2021, 03:27 AM #1
Striper69 Striper69 is offline
Banned
 
Join Date: Jan 2014
Location: Iowa
Posts: 1,358
Striper69 Striper69 is offline
Banned
 
Join Date: Jan 2014
Location: Iowa
Posts: 1,358
Long Distance Shooting

I'm planning on trying to shoot some deer from high on a Missouri River bluff. I used my range finder today and the deer will be 350 to 450 yards away. I'll be up pretty high as well. I'm going to zero my 300 Win Mag rifle at 6 inches above bulls eye at 100 yards. That should zero me at 300 yards approx. I want to get some practice in for next season because I hope to hunt Elk and Mule Deer in Montana on a friend's property.

My question is: will I have to compensate for the height I'm shooting from?
Striper69 is offline  
Old November 20th, 2021, 05:09 AM #2
steves1911's Avatar
steves1911 steves1911 is offline
Senior Member
 
Join Date: Dec 2011
Location: On a hill in Wv
Posts: 2,202
steves1911 steves1911 is offline
Senior Member
steves1911's Avatar
 
Join Date: Dec 2011
Location: On a hill in Wv
Posts: 2,202
Yes aim lower ..i dont have the exact formula right now but you need to know the cosine to be exact. At 300yds the diffrence wont be much unless its quite steep.
__________________
"one day you may find me dead face first in a ditch, but by god i will be surrounded by a pile of brass"
steves1911 is offline  
Old November 20th, 2021, 07:56 AM #3
E.Shell's Avatar
E.Shell E.Shell is offline
Senior Member
 
Join Date: Feb 2007
Location: Where everyone knows that Epstein Did Not Kill Himself.
Posts: 7,597
E.Shell E.Shell is offline
Senior Member
E.Shell's Avatar
 
Join Date: Feb 2007
Location: Where everyone knows that Epstein Did Not Kill Himself.
Posts: 7,597
Quote:
Originally Posted by steves1911 View Post
Yes aim lower ..i dont have the exact formula right now but you need to know the cosine to be exact.
An uncorrected uphill/downhill shot will go high, because the horizontal distance isn't as great as the line-of-sight distance.
The cosine for your angle of departure/shot angle from horizontal is multiplied against the line-of-sight distance to arrive at a horizontal distance.
Elevation is calculated for the horizontal distance.
Wind is calculated for line-of sight distance.
Quote:
At 300yds the diffrence wont be much unless its quite steep.
This *probably* true, but that also depends on the rifle's trajectory curve. With a .22-250, it is minimal, with a .22 Long Rifle, it is drastic. Gotta do the math to know what YOU have to do.
__________________
If you think politicians are "stupid", YOU are the one buying the illusion.

The beatings will continue until morale improves.
E.Shell is offline  
Old November 20th, 2021, 08:28 AM #4
davsco's Avatar
davsco davsco is offline
Senior Member
 
Join Date: Oct 2010
Location: Loudoun, VA
Posts: 7,261
Images: 4
davsco davsco is offline
Senior Member
davsco's Avatar
 
Join Date: Oct 2010
Location: Loudoun, VA
Posts: 7,261
Images: 4
Some rangefinders compensate for angles, check yours
davsco is offline  
Old November 20th, 2021, 08:33 AM #5
davsco's Avatar
davsco davsco is offline
Senior Member
 
Join Date: Oct 2010
Location: Loudoun, VA
Posts: 7,261
Images: 4
davsco davsco is offline
Senior Member
davsco's Avatar
 
Join Date: Oct 2010
Location: Loudoun, VA
Posts: 7,261
Images: 4
Best answer is to put a target out there and see where you're actually hitting, then u know for sure.
davsco is offline  
Old November 20th, 2021, 09:31 AM #6
lazarus lazarus is online now
Senior Member
 
Join Date: Jun 2015
Posts: 7,835
lazarus lazarus is online now
Senior Member
 
Join Date: Jun 2015
Posts: 7,835
Quote:
Originally Posted by davsco View Post
Some rangefinders compensate for angles, check yours
And you’ll need one, ideally that does!

Even with 300wm the difference between 350yds and 450yds is pretty pronounced. Add in the difference for the vertical…
lazarus is online now  
Old November 20th, 2021, 10:11 AM #7
steves1911's Avatar
steves1911 steves1911 is offline
Senior Member
 
Join Date: Dec 2011
Location: On a hill in Wv
Posts: 2,202
steves1911 steves1911 is offline
Senior Member
steves1911's Avatar
 
Join Date: Dec 2011
Location: On a hill in Wv
Posts: 2,202
Quote:
Originally Posted by davsco View Post
Some rangefinders compensate for angles, check yours
This!!!
A good rangefinder is priceless especially hunting across steep terrain that has a way of making everything seem farther away then it really is.
__________________
"one day you may find me dead face first in a ditch, but by god i will be surrounded by a pile of brass"
steves1911 is offline  
Old November 20th, 2021, 10:22 AM #8
Johnny5k Johnny5k is offline
Member
 
Join Date: Nov 2020
Posts: 232
Johnny5k Johnny5k is offline
Member
 
Join Date: Nov 2020
Posts: 232
Yep, It is just physics. I believe it is called the HCD or Horizontal Component Distance. So your drop is based on this number and not the total range. You can calculate this with trigonometry, using the range and any other value of the right triangle created, with the correct formula.

Range finders will use the angle to calculate HCD (mine will), but if you know the exact elevation difference, you can calculate that way as well.

Shooting at a 45 degree angle should give you a drop that is equal to about half of the normal drop, compared to the same distance to target on a flat range. Shooting up or down hill shouldn't matter much.
Johnny5k is offline  
Old November 20th, 2021, 11:58 AM #9
E.Shell's Avatar
E.Shell E.Shell is offline
Senior Member
 
Join Date: Feb 2007
Location: Where everyone knows that Epstein Did Not Kill Himself.
Posts: 7,597
E.Shell E.Shell is offline
Senior Member
E.Shell's Avatar
 
Join Date: Feb 2007
Location: Where everyone knows that Epstein Did Not Kill Himself.
Posts: 7,597
Quote:
Originally Posted by Johnny5k View Post
Yep, It is just physics geometry. I believe it is called the HCD or Horizontal Component Distance. So your drop is based on this number and not the total range. You can calculate this with trigonometry, using the range and any other value of the right triangle created, with the correct formula.

Range finders will use the angle to calculate HCD (mine will), but if you know the exact elevation difference, you can calculate that way as well.

Shooting at a 45 degree angle should give you a drop that is equal to about half 70% of the normal drop, compared to the same distance to target on a flat range. Shooting up or down hill shouldn't matter much.
Cleaned that up a little for you. 70% because the cosine for 45o is 0.707.

If you want to work this solution exactly, as needed for true long range, we would use the 'scope offset method', which uses come-up dope vs simple distance correction and takes into account the difference in vantage point between the scope and bore axes.

For hunting distances, the Rifleman's Rule I stated above gets us close enough.
__________________
If you think politicians are "stupid", YOU are the one buying the illusion.

The beatings will continue until morale improves.
E.Shell is offline  
Old November 20th, 2021, 12:10 PM #10
Park ranger Park ranger is online now
Senior Member
 
Join Date: Dec 2015
Posts: 1,558
Park ranger Park ranger is online now
Senior Member
 
Join Date: Dec 2015
Posts: 1,558
Put it in JBM ballistics to see the delta
Park ranger is online now  
Closed Thread

  Home Page > Forum List > Topics of Interest > Outdoor Sports


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:18 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
© 2021, Congregate Media, LP Privacy Policy Terms of Service