Comments on: Calculating Wind Drift (When You Don’t Have A Working Device)

By: Bob

Bob — Thu, 23 Jun 2016 15:58:36 +0000

Bryan
Apologies for incorrect name spelling.
Used the UK version!
Bob

By: Bob

Bob — Thu, 23 Jun 2016 15:03:32 +0000

Bryan
Sorry for using Brian, UK spelling.
Bob

By: Bob

Bob — Thu, 23 Jun 2016 08:27:02 +0000

Brian
Using the Hornady online calculator in G7 mode with BC 0.26, 175 gn and 2800fps seems to confirm my comments.
I normally use a G1 model (Perjesa or Quickload which gives similar results and seems to work in practice for me at shorter ranges on smaller targets (< 400yds). I appreciate the ~4 factor it is only an approximation and will get you on the target at longer ranges.
Best regards
Bob

By: Kevin

Kevin — Wed, 22 Jun 2016 20:07:28 +0000

Teach them to read a wind chart and mirage.

By: Bryan Litz

Bryan Litz — Wed, 22 Jun 2016 13:36:03 +0000

Bob,
Can you share the details of your example so we can consider it further?
There are some cases where the MOA error is high at shorter ranges, but the resulting inches of miss is usually less than 6″.
I admit there is some error in this approximation. It’s not intended to be perfect, but a simple, easy to remember guideline to get you close if you have nothing better to go by.
Good shooting,
-Bryan

By: Bob

Bob — Wed, 22 Jun 2016 10:24:29 +0000

This seems fine for 1000yd but wind drift and bullet drop is not a constant for all ranges.
At 1000 yds the division factor (drop/bc+2) ie 4 is correct.
However at 300 yds the factor is approximately 2 and at 700 yds it is approximately 3.

By: Matt

Matt — Tue, 21 Jun 2016 23:41:00 +0000

Don’t forget to factor in aerodynamic reflection wind formula as taught by Todd Hodnett. To get the complete details listen to Precision Rifle podcast episode 46. Wind from the left will cause your Bullets to drop down .125 @ 100 yds. Wind from the right will cause the bullet to go up. This is to be added to your windage adjustment or horizontal adjustment.