MOA Adjustment

Clem Bronkoski

Well-Known Member
Joined
Jun 23, 2019
Messages
475
Location
Locust Gap, PA
This doesn't sound right to me. I'm limited to my long range shooting areas and my current range only goes to 300 yds. I've shot at 100, 200 and 300 yds and confirmed my zero and MOA correction. Now I was playing with the Hornady Ballistic Calculator and my correction and the calculator's results were spot on at 300 yds (4.7 MOA). What doesn't sound right is that when I introduce a 10 MPH 90* wind my MOA correction drops to 3.9! This correction changes as the angle of the wind changes. Should I be using that wind correction or just go my my actual results with zero wind?
 
On Ballistics AE my dope for 400 yards is 4.9. On Hornandys app it's 5.7. Can't figure that one out.
I verified my 400 yard dope and it's dead on at 5.
IMG_0829.jpeg
 
Yes, that sounds right. You must have also input that your rifle has a right hand twist. Try putting the 10 mph wind in from the opposite direction (270 degrees). The elevation correction will go the opposite direction - probably over 5 MOA in your case. You can find charts and explanations for this effect - one example below.

1733290917569.gif

 
OK I get it now but I can't find which direction my rifle twist on line. I found out that looking at the twist from the breech, if it turns clockwise it is a RH twist. I never realized that twist direction could have that much of an effect on trajectory in the wind.
BTW thanks for the responses. I guess you can teach an old dog new tricks!
 
Last edited:
Yes, that sounds right. You must have also input that your rifle has a right hand twist. Try putting the 10 mph wind in from the opposite direction (270 degrees). The elevation correction will go the opposite direction - probably over 5 MOA in your case. You can find charts and explanations for this effect - one example below.

View attachment 621890
So let's see if I understand this. If I have a RH twist like above and the wind is blowing right to left I would dial less MOA adjustment and that adjustment is determined by the actual force AND direction.
 
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