Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Long Range Scopes and Other Optics

Long Range Scopes and Other Optics Nightforce Optics


Reply

MOA readings

 
LinkBack Thread Tools Display Modes
  #1  
Old 04-02-2008, 10:47 PM
Junior Member
 
Join Date: Mar 2008
Posts: 10
MOA readings

All right, dumb question. Say your scope has 56 MOA of adjustment. What does that mean. Is that 56 inches up or down at a 100 yards if so, what about at 600 yards. Now when you turn the turrets to adjust for drop, do you have to figure the MOA at that distance or does it do it automatically when you do the math for the given yardage. Sorry for the elementry question, but I'm trying to figure out if a scope will have enough adjustment for the given distance......Thanks
Reply With Quote
  #2  
Old 04-03-2008, 03:29 AM
Gold Member
 
Join Date: Dec 2002
Location: mathias wv
Posts: 985
1 moa is 1.047" per 100 yards of range, so those 4 1/4 MOA clicks will move the bullet 1.047" at 100
2.094" at 200 (1.047"x2=2.094)
3.141" at 300 (1.047x3=3.141") and

9.1089" at 870 yards (1.047"x8.7=9.1089")

MOA= a unit of angular measurement equal to 1/60th of 1 degree which equals 1.0473" per 100 yards.
there are 21,600 MOA in a circle, and 1 moa at the end of your 24" muzzle is .00698", hope this helps
RR
__________________
Born to Hunt, Forced to Work!
Reply With Quote
  #3  
Old 04-03-2008, 05:25 AM
Platinum Member
 
Join Date: Mar 2007
Location: MN
Posts: 1,219
+ 1 for ridgerunner.
Most scopes are actually set up in inches per hundred- so you have to figure out which yours is. I know nikon, Busnell, Zeis (I think) and many others are set up in inches per hundred (4 clicks = 1 inch per hundred yards)
__________________
I used to re-load but now I "hand-load".
-- Well, at least I try --
Reply With Quote
  #4  
Old 04-03-2008, 11:04 PM
Junior Member
 
Join Date: Mar 2008
Posts: 10
OK, it's obvious that I am new to this MOA thing. If a scope has the 56 MOA adjustments, and my bullet drops say 58" at 600 yards, is there enough adjustment to calculate for bullet drop. Again thanks for the replies.......
Reply With Quote
  #5  
Old 04-03-2008, 11:23 PM
Platinum Member
 
Join Date: Mar 2007
Location: MN
Posts: 1,219
Yes. most likely
60 inches at 600 yards is 10 inches per hundred yards. Inches Per hundred Yards (IPHY) is very close to MOA (1.047" per 100). If your scope has 58 MOA adjustement, you will likely have about 29 MOA of elevation (half of the total MOA of adjustment). I can't say for sure because sometimes scopes are mounted in such a way that you use up more of the elevation adjusment to atain a zero because the scope is mounted at a slight angle. BUT, most of the time your scope and bore will be paralell to eachother allowing you approximately half of your total adjustment to be useful in elevation adjustment after you are zerod in at 100 yards (half of the ajustment would be available for raising your crosshair and half would be avialable for lowering your crosshair).

When we say Inches Per Hundred Yards (IPHY), it is just that: so many inches of elevation for every hundred yards. So for the next few examples we will use the following number that I pulled out of my hat - 15 (IPHY). If you take 15 inches per hundred (what many incorectly call MOA), for every hundred yards you move away - you multiply the moa by that number inorder to atain the actual drop at a certain range. Ie. if you are at 100 yards you take 15 (IPHY) x 1 = 15 inches. if you are at 300 yards you take 15 (IPHY) x 3 = 45 inches. if you are at 800 yards you take 15 (IPHY) times 8 = 120 inches and so on.

I decided to add this to help clairfy the difference; if you take the same case in MOA, it would be 15 moa is (15 x 1.047 x how many hundred yards). Ie. at 100 yards you take 15 x 1.047 x 1 = 15.7". 15 MOA at 300 yards is 15 x 1.047 x 3 = 47.1". 15 MOA at 800 is 15 x 1.047 x 8 = 125.6".

here is where it gets tricky 1 MOA is acutally 1.047 inches per hundred yards. This means vertually nothing at close and mid range. However, when you start to adjust your scope 15-20 units (MOA or IPHY)and are trying to hit a target at several hundred yards away. that .047" per unit per hundred yards starts to add up in a hurry. My 300 wsm with a zero at 200 will miss a 600 yard target by something like a foot ( slight exageration I guess) if I am using calcuations for MOA and adjusting a scope that is set for IPHY.
__________________
I used to re-load but now I "hand-load".
-- Well, at least I try --

Last edited by britz; 04-03-2008 at 11:57 PM. Reason: cuz
Reply With Quote
  #6  
Old 04-03-2008, 11:24 PM
Gold Member
 
Join Date: Feb 2008
Location: Sonoma County, CA
Posts: 824
I'm pretty new to the MOA concept as well but what is helping me is to just consider MOA as 1" @ 100 yds. I am using this initially just to help me understand the concept. Yes I understand that 1.047 is technically correct, but that will come in time.

When you adjust your scope 1 MOA, that moves your point of impact 1" @ 100 yds. That same 1 MOA adjustment moves your POI 2" @ 200 yds, 6" @ 600 yds, etc. So the way I understand it is moving your scope 56 MOA would be 56" @ 100 yds.

If you needed to adjust for a bullet drop of 2" @ 100 yds, that would be 2 MOA. If you needed to adjust for a bullet drop of 2" @ 200 yds, that would only be a 1 MOA adjustment.

I hope this helps to get you started. Maybe someone like Shawn will chime in and give us all a quick lesson.
Reply With Quote
  #7  
Old 04-04-2008, 12:05 AM
Silver Member
 
Join Date: Oct 2006
Location: Oregon City, OR
Posts: 481
Easy but not Precise

I use the 1 inch - 1 MOA @ 100yrd.
How i do it. Run your drop chart like you did 58" come ups for 600yrds. Divide 58 by 6 = 9.66 MOA. I would round it to the nearest .25 moa assuming your scope it 4 clicks per 1 MOA. I would try 9.5 MOA or 9.75.

Just drop the zeros and divied you inches by that number. for 550 yards divide by 5.5

Willys
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: MOA readings
Thread Thread Starter Forum Replies Last Post
Chrony readings vs published data Kris C Rifles, Bullets, Barrels and Ballistics 3 05-08-2009 08:46 PM
Weird ProChrono Readings buffalorancher Rifles, Bullets, Barrels and Ballistics 5 09-27-2007 12:33 PM
Strange (low) velocity readings while starting Ladder Alan Griffith Reloading 11 04-10-2006 10:36 AM
Oehler Velocity readings? Nicholas Rifles, Bullets, Barrels and Ballistics 7 06-20-2003 08:26 AM
Determining distance via GPS readings Dave King Rifles, Bullets, Barrels and Ballistics 7 07-20-2002 06:25 AM

Current Poll
Do You Shoot Rifle Competition?
YES - 33.66%
764 Votes
NO - 66.34%
1,506 Vote
Total Votes: 2,270
You may not vote on this poll.

All times are GMT -5. The time now is 11:28 AM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC