The Mildot Master® is an analog ballistic calculator developed for quickly calculating range to target using a mildot reticle. Therefore, the single most important aspect of its use is target size estimation. The shooter must become proficient in accurately estimating the size of various target objects. The only way to acquire this proficiency is through practice.
Once target size is estimated, the Mildot Master is used to perform the necessary calculations to determine range to target. Arrow 1 in the accompanying image shows a case where the target size in mils, in this case 1.75 is matched to the estimated target size, 36". Range to target is found by looking for the "Target Range" area and seeing where it lands on the yardage scale. In the example shown, arrow 2 shows a range of approximately 575 yards.
Once this is known, the Mildot Master can then be used to determine sight corrections in either Mils or MOA to compensate for bullet drop and/or wind drift. This is where the area on the back of the Mildot Master is used to affix ballistic data. This data is provided by the shooter based on their specific load/bullet and lists bullet drop at various distances, usually every 50 to 100 yards. This data should be obtained by the shooter by sighting in the rifle at the various ranges using their specific load. The data is then entered onto a Ballistic Data Strip which is attached to the back of the Mildot Master.
The Ballistic Data Strip is used to obtain an approximate bullet drop based on the estimated range. The bullet drop is then read on the front of the Mildot Master and aligns with the necessary adjustment in either Mils or MOA. The shooter can either dial in the adjustment or use hold-over. In the example shown, assuming the shooters load data shows a bullet drop of approximately 40" at 575 yards (note that the bullet drop will most likely need to be estimated unless the range is an exact match for data on the ballistic strip), arrow 3 shows an adjustment of approximately 6.8 MOA or 1.95 Mils. The elevation adjustments or "come-ups" can also be entered on the Ballistic Data Strip making the last calculation unnecessary.
Wind drift corrections are calculated the same way as bullet drop corrections. In this case the shooter needs to be able to perform wind drift estimations for their particular load/bullet. Wind is the second biggest effect on the bullet in flight but it is also the hardest to account for. What makes wind so hard to account for is the difficulty in determining exact wind speed and direction. Then the shooter has to determine how varying wind speeds and directions will effect the bullet. Finally, the shooter has to take into account wind gusts and lulls. Similar to target size estimation, this is another skill the shooter must master that will only improve with practice.
Finally, the Mildot Master can be used to estimate the deviation from horizontal for uphill/downhill shots and compensate for bullet drop in these situations. This is because the actual horizontal range is less than the line of sight range. The bullet drop must be adjusted for this difference to obtain a hit. Note that the effect is the same whether shooting uphill or downhill.
For those shooters who already own an optical or laser rangefinder and therefore don't need range estimation, the Mildot Master can be used to convert a bullet drop figure into a sight adjustment figure.
The Mildot Master has the following advantages over the use of a conventional handheld electronic calculator:
Check out this review and tutorial of the Mildot Master.