Range Report Drag on a 6.5 bullet?

[BigJohn141]

I am running Loadbase 3 to get my dope at the range, it a great program with many many inputs and variables. One of these said inputs is drag for a bullet which is at .500 by default, does anyone know how to figure or where to look up drag for different bullets and would this really make much difference when shooting? I am kinda leaning toward it doesnt when shooting 1000 and under but I just thought I would ask. Thanks

 

[JWV]

Re: Drag on a 6.5 bullet?

The ballistic coefficient makes a very big difference and especially at long ranges. Google and SH searches are the best way to find out BC's quick. Also, Bryan Litz would likely have the data available. Or tell us the what bullet you plan on using and I bet someone in here will chime in with field experience with said bullet.

 

[427Cobra]

Re: Drag on a 6.5 bullet?

Find the bullet your shooting at MidwayUSA, in the description is the Manufactures BC.

 

[Greg Langelius *]

Re: Drag on a 6.5 bullet?

Ballparking is a term I use to describe calculations. They get you into the ballpark, and that's really just about the practical limit of their value.

Oh, yes; they derive values of exquisite precision, but when time comes we need to rely on them, the numbers say one thing, and the bullet says something a bit different.

That's because we live in a world dominated by variables, and not by constants. The data values we input to our calcs tend to be either guestimates or instantaneous snapshots of transient phenomena. The result can only be as precise as the data we provide. The certainty of our calculated results depends upon taking values from an environment which is in a constant state of flux. Their accuracy is based on what we believe <span style="font-style: italic">was true</span> at the time we gleaned our inputs. They frequently tend to be <span style="font-style: italic">history</span> reports.

The real world only resembles our calculations a part of the time; the rest of the time, it's subtly <span style="font-style: italic">different</span>.

Greg

 

[bohem]

Re: Drag on a 6.5 bullet?

Which bullet are you shooting?

 

[BigJohn141]

Re: Drag on a 6.5 bullet?

Im shooting berger 140 VLDs and I know what the G1 and G7 BC is on them but LB3 has a separate input for drag under the BC inputs.


Well dang, nevermind lol. Turns out I just need to play with LB3 a little more. In the analyzer section it will tell me what I am asking, I have used the actual screen before but just looked and the actual BC numbers and didnt notice the drag entry.

images from the manual, who would have thought to look there

 

[BigJohn141]

Re: Drag on a 6.5 bullet?

A few quick button pushed later and it turns out my Drag coefficient (DC) is around .647ish which is exactly opposite of the way I figured it would go. Those are with inputs from my ballistics tables and me recalling weather conditions from memory so I need to get to the range to get some data and figure the actual numbers. Oh from the inputs I remembered it said I was running .616 G1 and .304 G7 which is pretty close to what a 140 VLD should be.

 

[9H_Cracka]

Re: Drag on a 6.5 bullet?

I once took a big drag on a 6.5 bullet. Didn't do much at all for me.

 

[Dodgefan]

Re: Drag on a 6.5 bullet?

If you get to playing with it you will see the effect on the trajectory. Generally speaking the sleeker the bullet the higher the drag coefficient. This is easier on the laptop then the mobile.