Hornady just dropped a new 4DOF podcast 10/5/23

JAS-SH

Gunny Sergeant
Full Member
Minuteman
Jun 5, 2020
744
1,288
Gotta love gold for free... The title is Backstory. The history, how it was put together, what inside, the code, the whys of all the things it calculates - accurately.

Pay attention to these words: "equations of motion" - they use that a lot. If I remember the number correctly they said the app uses 438 different parameters for each specifically modeled bullet. Another interesting thing is how zero angle came about. It's not a new thing but it is new to rifle shooting. Zero angle is basically a modern artillery calculator. Set it one time and as long as you enter the right environmental, including, cardinal direction, shot elevation angle and distance. The zero solution will be true anywhere in the world.

It's funny to hear these guys talk, especially about zero range vs. zero angle.

I remember myself saying the same thing - "something's wrong!" I first said it back in 1984. I zeroed my rifle perfectly before leaving Florida and went hunting in the WA Cascades. Once there I went to the range fired a group at 100 and it was WAY off. It really wasn't though. once I got back to Florida I reset the scope to the Florida adjustments and it was back to dead on.

It's nothing short of amazing what they have done with that app. Even more so: It's free gold!

The podcast:

 
Last edited:
While 4DOF is a pretty good program, the zero range vs zero angle is not really a huge leap forward. FFS introduced the concept of a 'fixed zero", many years ago to account for changes in the environment altering the zero range. One of the reasons we mostly use a 100 yard zero for precision rifles is because there is basically no drift of the zero range even going from Death Valley, CA to Leadville, CO. Your zero was not "way off" going to WY from FL, at least not if you zeroed at 100 yards. The fixed zero option would fixes the issue if you use a long range zero, but isirrelevant if you zero at 100.

When the zero range is extended to 300 or 500 yards, there will be a noticeable difference. Dope will of course be different.
 
  • Like
Reactions: Baron23