Few days back i was trying to zero my TX 200,MKIII, LH, & it took me quite a few shots to zero my rifle. Though it is said in many forums & youtube vdos to firmly fix the rifle to a vice & after firing a shot use the turrets to adjust the poi=poa. But i think this process is not applicable for a springer.
For that reason i thought of establishing a relation between mildot & number of clicks on the turret (may be done way back
). Now for the calculation part we can deduce that For determining the no of clicks on the scope to compensate the poi to poa we can use
No of Clicks required=MilradX14 where Mrad=0.98 Mildot (considering Mildot=Milrad)
We know that MilDot 6400 mils/circle whereas Milliradian or Mrad divides a full circle into 6,283 parts. So we can establish that 1Mildot=1.019Milrad, but for our ease of calculation we are considering Mildot=Milrad
We also know that Minute of Arc=1/21600 of a circle, so we can also establish a relation between Mildot & MoA. Therefore 1 MOA = 0.2908 MilRad for ease of calculation we will consider 1 MOA = 0.3 MilRad
Or MilRad=3.4 MoA
Here is a table of my shooting data where the datas of the first 5 columns are from ballistic calculator & the last column is used for calculating the datas manually
Dist Moa Mrad Inch Click Mil=Mrad Clicks=MradX14
10 -4.52 -1.31 -0.47 -18.1 -1.31 -18.34
15 -9.91 -2.88 -1.57 -39.6 -2.88 -40.32
20 -11.9 -3.46 -2.48 -47.6 -3.46 -48.44
25 -12.5 -3.64 -3.27 -50 -3.64 -50.96
30 -12.39 -3.6 -3.9 -49.6 -3.6 -50.4
35 -11.85 -3.45 -4.33 -47.4 -3.45 -48.3
So if I am not wrong then I guess we can use the formula simply to multiply the factor 14 to the mildot where the poi in respect to poa for scopes having 4 graduation adjustment of MoA for 1 inch @ 100 yds.
Secondly we can find out the deviation in poi to poa in terms of inch by using the following formula, where we can consider Mrad as to be mildot inrespect of poi to poa. This equation can also be used to measure the distance if poi to poa deviation is measured using a vernier calipers or any scale(Inch=MradXDistX36/1000).
Here the datas of the first three columns are from ballistic table
Dist Inch Mrad Inch=MradXDistX36/1000
10 -0.47 -1.31 -1.31X10X36/1000=0.4716
15 -1.57 -2.88 -1.555
20 -2.48 -3.46 -2.49
25 -3.27 -3.64 -3.276
30 -3.9 -3.6 -3.888
35 -4.33 -3.45 -4.347
Tried to calculate for making adjustments by using the mildots & distance, but ofcourse the calculations were made for same angle of shooting & scope magnification. I know these things might have been done way back & people might say having ballistic mobile applications, one doesnot need to consult such tables/calulations. But I would like to say that if we are aware of the basics then it gives pleasure to work out the unknown parameters, then you can always refer it with the ballistic calculator. I would like the senior members to shed some light & corrections required (if at all it is correct).
Regards Moulindu
