The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: General

Reply
 
Thread Tools Search this Thread
Old January 28, 2011, 12:30 PM   #1
davis21b
Member
 
Join Date: January 6, 2011
Location: Mississippi
Posts: 63
mil dots

Sorry yall but I have a scope that has mil dots but no clue how to use them. Please someone break it down to dummy terms for me lol.
davis21b is offline  
Old January 28, 2011, 01:07 PM   #2
Jim243
Senior Member
 
Join Date: January 5, 2009
Location: Just off Route 66
Posts: 5,067
Not sure anyone really understands the math.

This will help.
http://www.snipercountry.com/articles/mildot_moa.asp

About 3 1/2 inches at 100 yards.

It is really a function of MOA and not Military. It will be different at different ranges 200 yards, 300 yards. The easy way is to test it out at different ranges fire one shot at center of the retical then move your sight up one Mil-dot and measure the difference, do that again with 2 mil dots, 3, 4 . That will give you the number of inches for each mil-dot change. Helps with hold over when shooting, but you need to know the range you are shooting at.

Jim


All my scopes are Mil-dot or P-4, I personally like the P-4 rectical better.
__________________
Si vis pacem, para bellum

Last edited by Jim243; January 28, 2011 at 01:21 PM.
Jim243 is offline  
Old January 28, 2011, 01:33 PM   #3
rugerdude
Senior Member
 
Join Date: July 6, 2004
Location: Tulsa, Oklahoma
Posts: 1,443
Mil dots are a good way to get your target range fairly quickly.

1 mil represents 1 meter at one thousand meters, or one yard at a thousand yards. You can determine range to target using the mil formula.

Example: My target is a standing man, who's shoulders measure 19" in width, or roughly half a meter. He appears to be 1 mil wide withing the scope.

0.5 (width of target in meters) divided by 1 (width in mils) = 0.5 (multiply this number by 1,000 to get range in meters).

Again, if my 0.5m wide target is 2 mils wide in my scope, then I take 0.5 (meters) and divide it by 2(mils) and get 0.25 which I then multiply by 1,000 to get my range in meters, which would be 250.

To get yards, simply substitute target width in yards and the range will be yards.

Human targets are only one thing you can use. If you happen to know the average width of a window or doorway you can use that to get range as well.

The only mil dot scope I've used was a leupold MK4 M3 10x42, and each dot was .25 mills in width, with 1 mil spaces between the center of the dots.
__________________
"The SKS is a rifle, made the way they should be, out of a heavy block of crappy commie steel, set in an inletted semi-reshaped 2x4."

Not my quote but I agree completely.
rugerdude is offline  
Old January 28, 2011, 02:23 PM   #4
theinvisibleheart
Senior Member
 
Join Date: December 19, 2005
Location: virtual internet world with a Daisy Red Ryder, LOL
Posts: 683
based on simple ratio

it's based on simple ratio that that 1 yard object is equal to 1 mil at 1000 yards.

So if you have a 2 yard object (or 72 inches) and it takes 2 mils, then range=1000 yards.

OTOH, if the 2 yard object takes 4 mils, then the range would be 500 yards, and so on.

Basically, you have to know the size of the object you are ranging in mils and either in actual inches/yards, and then you can calculate the range in yards using simple ratio or table or software.
theinvisibleheart is offline  
Old January 29, 2011, 05:04 AM   #5
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,282
Another thing to remember,most scopes will change the value between dots as you change the variable power,unless the mil reticle gets really small on low power.It only tells the truth on max power.
HiBC is offline  
Old January 29, 2011, 05:39 AM   #6
jgcoastie
Senior Member
 
Join Date: February 15, 2009
Location: Kodiak, Alaska
Posts: 2,118
Mil-dots are not intended to be used as bullet-drop compensation aiming points. If they were intended for bullet-drop compensation, then why in the heck are they used in spotting scopes???

Mil-dot reticles are intended to be used to calculate range, or distance, to your intended target.

The formula is centered around using meters for units of measurement, trust me, it's a lot simpler that way. One mil is measured from the center of one dot to the center of the next dot. Here's the formula on the card that came with my Vortex:

Height or width of target in meters x 900 = Range to target in Meters
Height or width of target in mils

Example: Ranging a tree that is known (or approximated) to be 1 meter wide (1 meter = 3.280 feet)

1meter x 900 = 450 meters (492.12 yards)
2 mils

If you must convert the range to your target to yards, multiply your range (in meters) by 1.0936, that will give you your range in yards.

On a fixed power scope, you obviously don't have to worry about what magnification setting to use b/c there's only one. Also, in a riflescope with a First Focal Plane (FFP) reticle, you don't have to worry about magnification settings, one mil @ 4x will be the same as one mil @ 16x, the reticle will appear to get bigger as you increase magnification and get smaller as you decrease it. The value (distance) between the mils remains the same.

On a typical variable power mil-dot scope, the reticle stays the same size throughout the magnification range. These scopes have their reticles in the Second Focal Plane and must be set to a particular magnification setting (usually indicated by the manufacturer in the paperwork in the original box) for the distance between the mils in the reticle to accurately measure sizes of objects at various ranges.

On my 4-16x50mm Vortex (second focal plane), it must be set to 9x for the mils to be accurate for measurement.
__________________
"To preserve liberty, it is essential that the whole body of the people always possess arms, and be taught alike, especially when young, how to use them." -Richard Henry Lee, Virginia delegate to the Continental Congress, initiator of the Declaration of Independence, and member of the first Senate, which passed the Bill of Rights.

Last edited by jgcoastie; January 29, 2011 at 05:53 AM.
jgcoastie is offline  
Old January 29, 2011, 09:59 AM   #7
theinvisibleheart
Senior Member
 
Join Date: December 19, 2005
Location: virtual internet world with a Daisy Red Ryder, LOL
Posts: 683
mildot at only 1 magnification setting

it depends on whether mildot is at 1st focal plane or 2nd.

With most mildot optics, mils are placed at 2nd and therefore, work at only one magnification setting.
theinvisibleheart is offline  
Old January 30, 2011, 10:50 PM   #8
JGant
Member
 
Join Date: September 25, 2010
Posts: 33
Put the effort into learning the mil-dot sys.....you'll never regret it...
JGant is offline  
Old January 31, 2011, 12:16 AM   #9
doofus47
Senior Member
 
Join Date: June 9, 2010
Location: live in a in a house when i'm not in a tent
Posts: 2,483
Remember those algebraic formulas that you never thought you'd use in 8th grade...?

Quote:
Example: My target is a standing man, who's shoulders measure 19" in width, or roughly half a meter. He appears to be 1 mil wide withing the scope.

0.5 (width of target in meters) divided by 1 (width in mils) = 0.5 (multiply this number by 1,000 to get range in meters).

Again, if my 0.5m wide target is 2 mils wide in my scope, then I take 0.5 (meters) and divide it by 2(mils) and get 0.25 which I then multiply by 1,000 to get my range in meters, which would be 250.
Example A above: .5/1(1000m/y)=Distance (500m/y)
Example B above: .5/2(1000m/y)=Distance (250m/y)

Mildots give your a known measure and just ask you to do the math to estimate distance based upon a known (or average guess) number used as a constant 1/1000.

I use ratios b/c geometry is easy for me; maybe the following example is easier. It may not be, but it's how I do mildots/range reticles.

I have a pair of WW2 binoculars with hash lines in the lens. I know (from measuring stuff across the field from my house) that the space between the center + and the small hash to the left or right is 5' at a distance of 300 yards.
I know that if I see something that fills the gap across the width of that center + to the small hash line the object/distance is either:
5' wide and 300 yards away:
2.5' wide and 150 yards away
10' wide and 600 yards away

If I see something that I KNOW is 5' across (like a bull elk rack) and it fills about half the distance of the small hash, then I can guesstimate that it is 600 yards away. All elk racks are not 5' across, etc, but it gives you an estimate you can work with. I know I can't make a 600 yards shot, so I pack my lunch and start hiking.

If you want to expand the math and use the vetical axis:
I know that a 6' person will be 6/5 of a small hash at 300 yards or a full small hash at 360 yards.

Hope this helps.
doofus47 is offline  
Old January 31, 2011, 06:28 AM   #10
SadistAssassin
Senior Member
 
Join Date: October 6, 2010
Location: Fairbanks, AK
Posts: 219
Also don't forget to do all this ranging well before you plan to shoot...for example, if you were in a hunting blind over looking a field, before you start to look for animals, use your scope to find the range of different points in your field of fire ( a tree or a grassy knoll)...when a target shows up anywhere in FOF, you'll know the distance immediatley because you will have already ranged the whole area
SadistAssassin is offline  
Old January 31, 2011, 11:07 AM   #11
doofus47
Senior Member
 
Join Date: June 9, 2010
Location: live in a in a house when i'm not in a tent
Posts: 2,483
Quote:
Also don't forget to do all this ranging well before you plan to shoot
Excellent point.
Before hunting season, I did a little hiking with my binoculars and my GPS. I would pick an object, play "guess that distance" with the binoculars and then hike over with my GPS and check my estimate.
It's humbling at first, but then the (guess)timating comes more naturally and your (my) math improves.
doofus47 is offline  
Old January 31, 2011, 11:22 AM   #12
thesheepdog
Senior Member
 
Join Date: May 12, 2010
Location: DFW Texas
Posts: 1,996
Try this:

http://www.shooterready.com/moademo.html
__________________
Krav Maga/Judo
Qualified Rifleman/Marksmanship Instructor/Lic. Medic
"There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit" Romans 8:1
thesheepdog is offline  
Old January 31, 2011, 02:21 PM   #13
emcon5
Senior Member
 
Join Date: July 10, 1999
Location: High Desert NV
Posts: 2,850
Quote:
Mil-dots are not intended to be used as bullet-drop compensation aiming points.
Just because it is not the intended use, doesn't mean it can't be used for that. I have a Mil-Dot scope on my long range rig, but I don't use it for ranging in the traditional method, as my favorite targets are too small to accurately range using the mil-dot system beyond about 300 yards, and frankly my eye is good enough that close.

What I did is using calculated ballistics, I use the mil-dots as aiming reference points for known ranges. It is easier to show than explain, so here is my cheat sheet:



So if I estimate the target is ~400 yards away, I hold halfway between the first and second dots, and hold into the wind as needed.

It works pretty well.
emcon5 is offline  
Old January 31, 2011, 03:54 PM   #14
brotus2
Senior Member
 
Join Date: November 8, 2009
Location: Panama City Beach
Posts: 269
bump to save
brotus2 is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 -5. The time now is 04:35 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.09456 seconds with 10 queries