Range Report "Backing into" a BC - Describe your method

[ReaperDriver]

Great discussions in several threads on the value and limitations of ballistic programs - and as has been said manytimes here, nothing replaces shooting your load under actual conditions to verify its performance.

However, I've read many of the Hide sages refer to "backing into a BC" or tweaking your program so it more closely matches your actual dope at various ranges. My question is: how do you guys go through that process? Do you work with changing only BC? Only MV? Both? What kind of range increments of Dope would you say is minimum to use to tweak the program to 1000yds?

Just interested in your process? Thanks

 

[ReaperDriver]

Re: "Backing into" a BC - Describe your method

No one?

 

[Jeff in TX]

Re: "Backing into" a BC - Describe your method

PM on the way

 

[LoneWolfUSMC]

Re: "Backing into" a BC - Describe your method

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ReaperDriver</div><div class="ubbcode-body">Do you work with changing only BC? Only MV? Both?</div></div>

I have never attempted this, but I would say if you are trying to get a correct BC, don't change the MV. MV is much easier to measure than BC. Whatever your chronograph says is what you should enter. That will be a known value not a variable.

 

[Lindy]

Re: "Backing into" a BC - Describe your method

Agree with Lonewolf. Measure the muzzle velocity as accurately as you can, which also involves testing the change of muzzle velocity with temperature.

Then manipulate the BC to get the results to match your long-distance shooting data. As I noted in my article , this should be done as a velocity where the bullet is still well supersonic, to avoid inconsistencies which may accompany bullet behaviour in the transonic region.

It ain't perfect, and as I noted elsewhere may be compensating for several different kinds of inaccuracies.