Mill Dot & TMR

Posted by Bill on May 6, 2012 in Articles, Bill | 0 comments

The mil dot reticle has become the standard in tactical rifle scopes. Versions of the Leupold Mark IV, Night Force and many other scopes give the users a reliable old school means of determining distances to targets. With proper practice and study, establishing leads for moving targets, and alternate aiming points for windage and elevation holds allows qualified shooters of any discipline the tool to place their shot precisely.

The Mil Dot and the TMR(Tactical Mil Recital) are a simple gauge that has a fixed angel. First we will discuss the Mil Dot. But first what is a Mil?…There are 2π (2 times Pi) radians in a circle or 360º. Dividing 360 by 2π gives us 57.3º per radian. A Mil is a milliradian or 1/1000 of a radian. 1 Mil is 0.057º, or at 100 yards is 3.6 inches. Using basic math (not the same math taught in inner city public schools), the formula is range in yards= Object height in inches x 27.8/Mils. Say an object or target is 72” tall. One Mil will be = to 2000 yards…Out of range for most shooters.

The next situation is a tall 6 foot jihadie who fits perfectly within 2.5 dots. The formula is Height in Inches x 27.8 / Mils = Distance in yards. 72” x 27.8/2.5 = 800 yards

Note: The range estimation is only as accurate as your size estimation. Say the jihadie is only 62” tall and measures 2.5 Mils. 62×27.8/3= 689 Yards. This error can lead to a 308 168gr bullet at this range striking over 3.9′ high.

Other objects like wheel rims are more commonly sized than people or wild game. The standard wheel rim is 15”. Say the rim fits within 2 ½ Dots the range would be 15*27.8/2.5=166.8 or 167 yards.

Military snipers are well versed in standard object sizes. Knowing the size of a garbage can, 55 gal drum, common car or doorway can be invaluable in range estimation.

Both hunters and snipers are versed in the concepr of hold over and kentecky windage. Both the Mil Dot and TMR allows for increasec accuracy. In the next example the Jihadie is 500 yards away and the rifle is sighted in for 300 yards. Wind is 10 mph from left to right. According to the ballistic chart this bullet will drop 37″ and drift 26″ to caculate the hold over in Mils simply use this formula: Bullet (Drop from Zero in Inches -6)/((Range in Yards/100)x3.5) or (37-6)/(5×3.5)=1.77 Mils. The Lead formula is the same (26-6)/(5×3.5)=1.14 Mils.

The TMR or Tactical Mil Retical is an evolution of the Mil Dot with more percise Mil marks. The following pic shows the similarities and improvements.